N-Q 1 final.htm BR NATIONAL MUNICIPAL FUND National Muni -- Converted by SEC Publisher, created by BCL Technologies Inc., for SEC Filing

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED
MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number 811-02688

Name of Fund: BlackRock Municipal Bond Fund, Inc.
BlackRock High Yield Municipal Fund
BlackRock Municipal Insured Fund
BlackRock National Municipal Fund
BlackRock Short-Term Municipal Fund

Fund Address: 100 Bellevue Parkway, Wilmington, DE 19809

Name and address of agent for service: Donald C. Burke, Chief Executive Officer, BlackRock
Municipal Bond Fund, Inc., 800 Scudders Mill Road, Plainsboro, NJ, 08536. Mailing
address: P.O. Box 9011, Princeton, NJ, 08543-9011

Registrant’s telephone number, including area code: (800) 441-7762

Date of fiscal year end: 06/30/2008

Date of reporting period: 01/01/2008 – 03/31/2008

Item 1 – Schedule of Investments

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
Alabama - 0.8%    Alabama Incentives Financing Authority, Special Obligation Revenue         
    Refunding Bonds, Series A, 6%, 10/01/29 (a)    $ 3,820    $ 3,994,727 
   
 
 
    Jefferson County, Alabama, Public Building Authority, Lease Revenue         
    Bonds, 5.125%, 4/01/21 (a)        3,525    3,249,310 
   
 
 
 
    Mobile, Alabama, Industrial Development Board, Environmental         
    Improvement Revenue Refunding Bonds (International Paper Company         
    Project), AMT, Series A, 6.35%, 5/15/16        500    512,095 
   
 
 
 
    Selma, Alabama, IDB, Environmental Improvement Revenue             
    Refunding Bonds (International Paper Company Project), AMT,             
    Series A, 6.70%, 2/01/18        2,500    2,580,125 
   
 
 
 
    Tuscaloosa, Alabama, Special Care Facilities Financing Authority,         
    Residential Care Facility Revenue Bonds (Capstone Village, Inc. Project),         
    Series A, 5.875%, 8/01/36        3,400    2,984,792 
   
 
 
 
                13,321,049 
 
 
 
 
Arizona - 1.9%    Arizona Health Facilities Authority Revenue Bonds (Catholic Healthcare         
    West), Series A, 6.625%, 7/01/20        4,000    4,402,000 
   
 
 
 
    Maricopa County, Arizona, IDA, Education Revenue Bonds (Arizona Charter         
    Schools Project 1), Series A, 6.75%, 7/01/29        3,100    2,777,228 
   
 
 
 
    Maricopa County, Arizona, IDA, Health Facilities Revenue Refunding Bonds         
    (Catholic Healthcare West Project), Series A, 5%, 7/01/21        1,625    1,623,310 
   
 
 
 
    Maricopa County and Phoenix, Arizona, IDA, S/F Mortgage Revenue Bonds,         
    AMT, Series A-2, 5.80%, 7/01/40 (c)(d)        7,750    8,036,750 
   
 
 
 
    Peoria, Arizona, Improvement District Number 8801, Special Assessment         
    Bonds, 7.30%, 1/01/09        190    194,167 
   
 
 
 
    Peoria, Arizona, Improvement District Number 8801, Special Assessment         
    Bonds, 7.30%, 1/01/11        395    403,398 
   
 
 
 
    Peoria, Arizona, Improvement District Number 8802, Special Assessment         
    Bonds, 7.20%, 1/01/10        430    439,034 
   
 
 
 
    Peoria, Arizona, Improvement District Number 8802, Special Assessment         
    Bonds, 7.20%, 1/01/13        510    520,715 
   
 
 
 
    Phoenix, Arizona, IDA, Airport Facility, Revenue Refunding Bonds         
    (America West Airlines Inc. Project), AMT, 6.30%, 4/01/23        3,685    3,315,247 
   
 
 
 
    Pinal County, Arizona, IDA, Wastewater Revenue Bonds (San Manuel Facilities         
    Project), AMT, 6.25%, 6/01/26        500    482,090 
   
 
 
 
    Prescott Valley, Arizona, Improvement District, Special Assessment Bonds         
    (Sewer Collection System Roadway Repair), 7.90%, 1/01/12        323    333,207 
 
 
 
 
Portfolio Abbreviations             
 
 
 

To simplify the listings of BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund's portfolio holdings in the Schedule of Investments, we have abbreviated the names of many of the securities according to the list below.

AMT    Alternative Minimum Tax (subject to)    IDA    Industrial Development Authority 
ARS    Auction Rate Securities    IDB    Industrial Development Board 
CARS    Complementary Auction Rate Securities    IDR    Industrial Development Revenue Bonds 
COP    Certificates of Participation    M/F    Multi-Family 
CP    Commercial Paper    PCR    Pollution Control Revenue Bonds 
EDA    Economic Development Authority    S/F    Single-Family 
GO    General Obligation Bonds    SAVRS    Select Auction Variable Rate Securities 
HFA    Housing Finance Agency    VRDN    Variable Rate Demand Notes 

1

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    Tucson, Arizona, IDA, Senior Living Facilities Revenue Bonds         
    (Christian Care Tucson Inc. Project), Series A, 6.125%, 7/01/10 (b)(e)    $ 3,515     $3,835,709 
   
 
 
    University of Arizona, COP (University of Arizona Parking and Student         
    Housing), 5.75%, 6/01/09 (a)(b)        1,000    1,045,250 
   
 
 
 
    University of Arizona, COP (University of Arizona Projects), Refunding, Series         
    A, 5.50%, 6/01/18 (a)        265    280,309 
   
 
 
 
    Vistancia Community Facilities District, Arizona, GO, 6.75%, 7/15/22    3,000    3,141,210 
   
 
 
    Vistancia Community Facilities District, Arizona, GO, 5.75%, 7/15/24    2,125    2,136,093 
   
 
 
                32,965,717 
 
 
 
 
Arkansas - 0.1%    Arkansas State Student Loan Authority Revenue Bonds, AMT,         
    Sub-Series B, 7.25%, 6/01/09        250    251,590 
   
 
 
 
    Jonesboro, Arkansas, Residential Housing and Health Care Facilities Board,         
    Hospital Revenue Refunding Bonds (Saint Bernards Regional Medical Center),         
    Series B, 5.90%, 7/01/16 (a)        200    201,586 
   
 
 
 
    North Little Rock, Arkansas, Health Facilities Board, Health Care         
    Revenue Bonds (Baptist Health), 5.50%, 7/01/16        250    255,598 
   
 
 
 
    Pine Bluff, Arkansas, Environmental Improvement Revenue             
    Refunding Bonds (International Paper Company Project), AMT,         
    Series A, 6.70%, 8/01/20        500    510,440 
   
 
 
 
    University of Central Arkansas, Housing System Revenue Bonds,         
    6.50%, 1/01/10 (b)(f)        250    272,655 
   
 
 
 
                1,491,869 
 
 
 
 
California - 14.5%    Agua Caliente Band of Cahuilla Indians, California, Casino Revenue Bonds,         
    6%, 7/01/18        2,500    2,501,400 
   
 
 
 
    Antelope Valley, California, Health Care District Revenue Bonds, VRDN,         
    Series A, 5.25%, 9/01/17 (k)        12,000    12,044,760 
   
 
 
 
    Belmont-Redwood Shores School District, California, GO (Election of 2005),         
    Series A, 5%, 8/01/32 (f)        10,000    10,038,600 
   
 
 
 
    California Health Facilities Financing Authority Revenue Bonds         
    (Sutter Health), Series A, 5.25%, 11/15/46        7,500    7,209,825 
   
 
 
 
    California Pollution Control Financing Authority, Solid Waste Disposal         
    Revenue Bonds (Waste Management Inc. Project), AMT, Series A-2,         
    5.40%, 4/01/25        6,000    5,458,920 
   
 
 
 
    California Pollution Control Financing Authority, Solid Waste Disposal         
    Revenue Bonds (Waste Management Inc. Project), AMT, Series C,         
    5.125%, 11/01/23        6,750    6,012,630 
   
 
 
 
    California Pollution Control Financing Authority, Solid Waste Disposal,         
    Revenue Refunding Bonds (Republic Services Inc. Project), AMT, Series C,         
    5.25%, 6/01/23        4,150    3,926,730 
   
 
 
 
    California Rural Home Mortgage Finance Authority, S/F Mortgage         
    Revenue Bonds (Mortgage-Backed Securities Program), AMT,         
    Sub-Series FH-1, 5.50%, 8/01/47        4,970    4,949,971 
   
 
 
 
    California Rural Home Mortgage Finance Authority, S/F Mortgage Revenue         
    Refunding Bonds (Mortgage-Backed Securities Program), AMT, Series A-2,         
    7%, 9/01/29 (c)(d)        45    45,748 
   
 
 
 
    California State, GO, 5.25%, 4/01/29        5    5,044 
   
 
 
 

2

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    California State, GO, Refunding, 5.75%, 5/01/10 (b)        $ 15    $ 16,202 
   
 
 
 
    California State, GO, Refunding, 5.75%, 5/01/30        115    118,197 
   
 
 
 
    California State, Various Purpose, GO, 5.25%, 11/01/27        10,000    10,183,400 
   
 
 
 
    California State, Various Purpose, GO, 5.50%, 11/01/33        14,100    14,379,321 
   
 
 
 
    California Statewide Communities Development Authority, Health Facility         
    Revenue Bonds (Memorial Health Services), Series A, 6%, 10/01/23    9,880    10,299,011 
   
 
 
    Chabot-Las Positas, California, Community College District, GO         
    (Election of 2004), Series B, 5%, 8/01/31 (a)        12,895    12,902,866 
   
 
 
 
    Chula Vista, California, Community Facilities District Number 06-1,         
    Special Tax Bonds (Eastlake Woods Area), Series A, 6.05%, 9/01/20    1,080    1,103,792 
   
 
 
    Chula Vista, California, Community Facilities District Number 06-1,         
    Special Tax Bonds (Eastlake Woods Area), Series A, 6.15%, 9/01/26    2,965    2,976,979 
   
 
 
    Chula Vista, California, IDR, Refunding (San Diego Gas & Electric Co.), AMT,         
    Series C, 5.25%, 12/01/27        10,000    9,712,700 
   
 
 
 
    Contra Costa County, California, Special Tax Bonds (Community Facilities         
    District Number 2001-01), 6%, 9/01/26        1,585    1,528,495 
   
 
 
 
    Contra Costa County, California, Special Tax Bonds (Community Facilities         
    District Number 2001-01), 6.10%, 9/01/31        1,200    1,150,932 
   
 
 
 
    Elk Grove, California, Poppy Ridge Community Facilities Number 3         
    Special Tax, Series 1, 6%, 9/01/08 (b)        3,100    3,180,972 
   
 
 
 
    Los Angeles, California, Unified School District, GO (Election of 2004), Series         
    H, 5%, 7/01/32 (f)        20,000    20,079,400 
   
 
 
 
    Los Angeles County, California, Metropolitan Transportation Authority, Sales         
    Tax Revenue Refunding Bonds, Proposition A, First Tier             
    Senior-Series A, 5%, 7/01/35 (a)        12,730    12,691,428 
   
 
 
 
    Metropolitan Water District of Southern California, Waterworks Revenue         
    Refunding Bonds, Series B, 5%, 7/01/35        10,000    10,053,000 
   
 
 
 
    Palomar Pomerado Health Care District, California, GO (Election of 2004),         
    Series A, 5.125%, 8/01/37 (g)        23,200    23,292,336 
   
 
 
 
    Poway, California, Unified School District, Special Tax Bonds         
    (Community Facilities District Number 6), Series A, 6.05%, 9/01/25    1,100    1,100,605 
   
 
 
    Riverside, California, Improvement Bond Act of 1915, Special Assessment         
    (Riverwalk Assessment District), 6.375%, 9/02/26        2,695    2,740,869 
   
 
 
 
    Roseville, California, Special Tax Bonds (Fiddyment Ranch Community         
    Facilities Number 1), 5.125%, 9/01/26        3,915    3,398,377 
   
 
 
 
    Roseville, California, Special Tax Bonds (Stoneridge Community Facilities         
    Number 1), 6%, 9/01/11 (b)        1,125    1,270,125 
   
 
 
 
    Roseville, California, Special Tax Bonds (Stoneridge Community Facilities         
    Number 1), 6.20%, 9/01/11 (b)        1,250    1,419,375 
   
 
 
 
    Roseville, California, Special Tax Bonds (Stoneridge Community Facilities         
    Number 1), 6.30%, 9/01/11 (b)        2,500    2,846,875 
   
 
 
 
    Sacramento, California, Special Tax (North Natomas Community Facilities),         
    Series 01-03, 6%, 9/01/28        2,200    2,134,440 
   
 
 
 
    Sacramento, California, Special Tax (North Natomas Community Facilities),         
    Series 4-C, 6%, 9/01/28        2,265    2,223,075 
   
 
 
 
    San Diego, California, Public Facilities Financing Authority,             
    Subordinated Water Revenue Refunding Bonds, 5%, 8/01/32 (g)    10,000    10,000,500 
   
 
 

3

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    San Francisco, California, City and County Redevelopment Agency, Community         
    Facilities District Number 6, Special Tax Bonds             
    (Mission Bay South Public Improvements Project), 6%, 8/01/21    $ 5,000     $5,026,450 
   
 
 
    San Francisco, California, City and County Redevelopment Agency, Community         
    Facilities District Number 6, Special Tax Bonds             
    (Mission Bay South Public Improvements Project), Series A, 6%, 8/01/25    2,500    2,462,725 
   
 
 
    San Francisco, California, Uptown Parking Corporation, Parking Revenue Bonds         
    (Union Square), 6%, 7/01/20 (g)        1,075    1,163,548 
   
 
 
 
    San Ramon Valley, California, Unified School District, GO (Election of 2002),         
    5%, 8/01/26 (f)        10,000    10,123,800 
   
 
 
 
    Santa Margarita, California, Water District, Special Tax Refunding Bonds         
    (Community Facilities District Number 99), Series 1, 6.20%, 9/01/09 (b)    1,030    1,111,731 
   
 
 
    Santa Margarita, California, Water District, Special Tax Refunding Bonds         
    (Community Facilities District Number 99), Series 1, 6.25%, 9/01/09 (b)    2,950    3,178,301 
   
 
 
    Santa Margarita, California, Water District, Special Tax Refunding Bonds         
    (Community Facilities District Number 99), Series 1, 6.20%, 9/01/20    2,650    2,707,081 
   
 
 
    Southern California HFA, S/F Mortgage Revenue Bonds, AMT, Series A, 5.80%,         
    12/01/49 (c)(d)        4,500    4,603,770 
   
 
 
 
    Tustin, California, Community Facilities District Number 07-1,         
    Special Tax Bonds (Tustin Legacy), 6%, 9/01/37        2,000    1,864,520 
   
 
 
 
                245,238,826 
 
 
 
 
Colorado - 1.6%    Boulder County, Colorado, Hospital Development Revenue Bonds (Longmont         
    United Hospital Project), 6%, 12/01/10 (b)(e)        500    544,490 
   
 
 
 
    Colorado HFA, Revenue Bonds (S/F Program), Series B-3, 6.55%, 10/01/16    200    206,518 
   
 
 
    Colorado HFA, Revenue Refunding Bonds (S/F Program), AMT,         
    Senior Series A-2, 7.50%, 4/01/31        200    207,982 
   
 
 
 
    Colorado HFA, Revenue Refunding Bonds (S/F Program), AMT,         
    Senior Series B-2, 7.10%, 4/01/17        80    82,970 
   
 
 
 
    Colorado HFA, Revenue Refunding Bonds (S/F Program), AMT,         
    Senior Series B-2, 7.25%, 10/01/31        640    687,430 
   
 
 
 
    Colorado HFA, Revenue Refunding Bonds (S/F Program), AMT,         
    Senior Series B-3, 6.80%, 11/01/28        20    20,358 
   
 
 
 
    Colorado HFA, Revenue Refunding Bonds (S/F Program), AMT,         
    Senior Series C-2, 7.25%, 10/01/31 (h)        275    279,312 
   
 
 
 
    Colorado HFA, Revenue Refunding Bonds (S/F Program), Senior Series A-3,         
    7.35%, 10/01/30        80    83,169 
   
 
 
 
    Colorado HFA, Revenue Refunding Bonds (S/F Program), Senior Series C-3,         
    6.75%, 10/01/21 (h)        445    478,660 
   
 
 
 
    Colorado HFA, Revenue Refunding Bonds (S/F Program), Senior Series C-3,         
    7.15%, 10/01/30 (h)        100    101,787 
   
 
 
 
    Colorado Health Facilities Authority, Revenue Refunding Bonds         
    (Christian Living Communities Project), Series A, 5.75%, 1/01/37    1,500    1,314,825 
   
 
 
    Colorado Water Resource and Power Development Authority, Small Water         
    Resources Revenue Bonds, Series A, 5.80%, 11/01/10 (b)(i)        350    379,316 
   
 
 
 
    Colorado Water Resource and Power Development Authority, Small Water         
    Resources Revenue Bonds, Series A, 5.80%, 11/01/20 (i)        200    208,536 
   
 
 
 

4

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    Elk Valley, Colorado, Public Improvement Revenue Bonds             
    (Public Improvement Fee), Series A, 7.35%, 9/01/31        $ 7,560    $ 7,658,658 
   
 
 
 
    Elk Valley, Colorado, Public Improvement Revenue Bonds             
    (Public Improvement Fee), Series B, 7.45%, 9/01/31        880    894,441 
   
 
 
 
    Larimer County, Colorado, Poudre School District Number R-1, GO,         
    6%, 12/15/10 (b)(i)        3,685    4,023,467 
   
 
 
 
    Plaza Metropolitan District Number 1, Colorado, Tax Allocation Revenue Bonds         
    (Public Improvement Fees), 8%, 12/01/25        7,700    8,034,642 
   
 
 
 
    Plaza Metropolitan District Number 1, Colorado, Tax Allocation Revenue Bonds         
    (Public Improvement Fees), 8.125%, 12/01/25        1,910    1,909,714 
   
 
 
 
                27,116,275 
 
 
 
 
Connecticut - 1.8%    Connecticut State Development Authority, Governmental Lease Revenue         
    Bonds, 6.60%, 6/15/14 (g)        1,000    1,003,240 
   
 
 
 
    Connecticut State Development Authority, Water Facility Revenue Bonds         
    (Bridgeport Hydraulic Company), AMT, 6.15%, 4/01/35 (a)        1,250    1,270,550 
   
 
 
 
    Connecticut State Development Authority, Water Facility Revenue Refunding         
    Bonds (Aquarion Water Company Project), AMT,             
    5.10%, 9/01/37 (j)        2,750    2,329,882 
   
 
 
 
    Connecticut State, HFA, Revenue Refunding Bonds (Housing Mortgage Finance         
    Program), Series C-1, 6.30%, 11/15/17        960    995,616 
   
 
 
 
    Connecticut State Health and Educational Facilities Authority Revenue Bonds         
    (Bridgeport Hospital), Series A, 6.625%, 7/01/18 (g)        1,000    1,004,960 
   
 
 
 
    Connecticut State Health and Educational Facilities Authority Revenue Bonds         
    (Waterbury Hospital Issue), Series C, 5.75%, 7/01/20 (e)        1,500    1,530,180 
   
 
 
 
    Connecticut State Health and Educational Facilities Authority Revenue Bonds         
    (Westover School), Series A, 5.70%, 7/01/10 (b)(e)        1,000    1,082,220 
   
 
 
 
    Connecticut State Health and Educational Facilities Authority,         
    Revenue Refunding Bonds (Eastern Connecticut Health Network),         
    Series A, 6.50%, 7/01/10 (b)(e)        12,045    13,245,164 
   
 
 
 
    Connecticut State Health and Educational Facilities Authority, Revenue         
    Refunding Bonds (Sacred Heart University), 6.625%, 7/01/26 (e)    640    644,096 
   
 
 
    Connecticut State Health and Educational Facilities Authority, Revenue         
    Refunding Bonds (University of Hartford), Series E, 5.50%, 7/01/22 (e)    5,710    5,883,812 
   
 
 
    Connecticut State Higher Education Supplemental Loan Authority, Revenue         
    Bonds (Family Education Loan Program), AMT, Series A,             
    5.50%, 11/15/20 (g)        460    464,467 
   
 
 
 
    Waterbury, Connecticut, GO, 6%, 2/01/09 (b)(e)        860    898,975 
   
 
 
 
                30,353,162 
 
 
 
 
Florida - 10.3%    Alachua County, Florida, IDR (North Florida Retirement Village), Refunding,         
    5.875%, 11/15/36        5,500    4,869,865 
   
 
 
 
    Anthem Park Community Development District, Florida,             
    Capital Improvement Revenue Bonds, 5.80%, 5/01/36        1,945    1,645,120 
   
 
 
 
    Ave Maria Stewardship Community District, Florida,             
    Capital Improvement Revenue Bonds, Series A, 5.125%, 5/01/38    2,000    1,505,820 
   
 
 
    Ave Maria Stewardship Community District, Florida, Revenue Bonds,         
    4.80%, 11/01/12        1,500    1,379,580 
   
 
 
 

5

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    Ballantrae, Florida, Community Development District,             
    Capital Improvement Revenue Bonds, 6%, 5/01/35    $ 1,640     $1,551,981 
   
 
 
    Bartram Springs Community Development District, Florida,             
    Special Assessment Refunding Bonds, 4.75%, 5/01/34 (e)        4,900    4,283,629 
   
 
 
 
    Beacon Tradeport Community, Florida, Development District,             
    Special Assessment Revenue Refunding Bonds (Commercial Project),         
    Series A, 5.25%, 5/01/16 (e)        1,670    1,718,046 
   
 
 
 
    CFM Community Development District, Florida, Capital Improvement Revenue         
    Bonds, Series B, 5.875%, 5/01/14        2,500    2,260,075 
   
 
 
 
    Duval County, Florida, School Board, COP, 5.75%, 7/01/17 (f)        2,725    2,838,006 
   
 
 
 
    Fiddlers Creek, Florida, Community Development District Number 2, Special         
    Assessment Revenue Bonds, Series A, 6.375%, 5/01/35        5,350    5,019,744 
   
 
 
 
    Fiddlers Creek, Florida, Community Development District Number 2, Special         
    Assessment Revenue Bonds, Series B, 5.75%, 5/01/13        600    582,000 
   
 
 
 
    Halifax Hospital Medical Center, Florida, Hospital Revenue Refunding and         
    Improvement Bonds, Series A, 5.25%, 6/01/26        7,000    6,630,680 
   
 
 
 
    Highland Meadows Community Development District, Florida,             
    Special Assessment Bonds, Series A, 5.50%, 5/01/36        1,135    885,765 
   
 
 
 
    Highlands County, Florida, Health Facilities Authority, Hospital         
    Revenue Bonds (Adventist Health System), ARS, VRDN, Series F,         
    6.01%, 11/15/35 (f)(k)        4,075    4,075,000 
   
 
 
 
    Hillsborough County, Florida, IDA, Exempt Facilities Revenue Bonds (National         
    Gypsum Company), AMT, Series A, 7.125%, 4/01/30        5,000    4,939,350 
   
 
 
 
    Hillsborough County, Florida, IDA, Hospital Revenue Bonds (Tampa General         
    Hospital Project), 5.25%, 10/01/41        16,845    15,623,064 
   
 
 
 
    Lee County, Florida, IDA, Health Care Facilities, Revenue Refunding Bonds         
    (Shell Point/Alliance Obligor Group), 5%, 11/15/29        2,000    1,697,180 
   
 
 
 
    Lexington Oaks, Florida, Community Development District,             
    Special Assessment Revenue Bonds, Series A, 6.70%, 5/01/33        1,075    1,095,715 
   
 
 
 
    Mediterra, Florida, South Community Development District,             
    Capital Improvement Revenue Bonds, 6.85%, 5/01/31        945    969,872 
   
 
 
 
    Middle Village Community Development District, Florida,             
    Special Assessment Bonds, Series A, 6%, 5/01/35        2,500    2,282,475 
   
 
 
 
    Midtown Miami, Florida, Community Development District,             
    Special Assessment Revenue Bonds, Series A, 6.25%, 5/01/37        6,625    6,157,408 
   
 
 
 
    New River Community Development District, Florida,             
    Capital Improvement Revenue Bonds, Series B, 5%, 5/01/13        1,000    912,820 
   
 
 
 
    Orange County, Florida, HFA, M/F Housing Revenue Bonds             
    (Loma Vista Project), Series G, 5.50%, 3/01/32        3,500    3,356,185 
   
 
 
 
    Orange County, Florida, Health Facilities Authority, Hospital Revenue Bonds         
    (Orlando Regional Healthcare), 5.70%, 7/01/26        1,000    896,240 
   
 
 
 
    Orlando-Orange County Expressway Authority, Florida, Expressway Revenue         
    Bonds, VRDN, Sub-Series A-3, 5.50%, 7/01/40 (a)(k)        14,045    14,045,000 
   
 
 
 
    Panther Trace Community Development District II, Florida,             
    Special Assessment Revenue Bonds, 5.125%, 11/01/13        10,000    9,201,400 
   
 
 
 
    Panther Trace Community Development District II, Florida,             
    Special Assessment Revenue Bonds, Series A, 5.60%, 5/01/35        4,900    4,006,877 
   
 
 
 

6

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    Park Place Community Development District, Florida,             
    Special Assessment Revenue Bonds, 6.75%, 5/01/32        $ 960     $971,837 
   
 
 
 
    Park Place Community Development District, Florida,             
    Special Assessment Revenue Bonds, 6.375%, 5/01/34        2,300    2,278,196 
   
 
 
 
    Saint Lucie, Florida, West Services District, Utility Revenue Refunding Bonds,         
    Senior Lien, 6%, 10/01/22 (g)        2,000    2,128,520 
   
 
 
 
    Sarasota County, Florida, Health Facilities Authority, Retirement Facility         
    Revenue Refunding Bonds (Village on the Isle Project), 5.50%, 1/01/27    780    703,895 
   
 
 
    Sarasota County, Florida, Health Facilities Authority, Retirement Facility         
    Revenue Refunding Bonds (Village on the Isle Project), 5.50%, 1/01/32    1,645    1,438,174 
   
 
 
    Seminole County, Florida, Water and Sewer Revenue Bonds, 5%, 10/01/36    23,435    23,119,565 
   
 
 
    Somerset Community Development District, Florida, Capital Improvement         
    Revenue Bonds, 5%, 5/01/15        2,575    2,308,333 
   
 
 
 
    Sterling Hill Community Development District, Florida, Capital Improvement         
    Revenue Refunding Bonds, Series B, 5.50%, 11/01/10        210    208,349 
   
 
 
 
    Stoneybrook West, Florida, Community Development District,         
    Special Assessment Revenue Bonds, Series B, 6.45%, 5/01/10    80    79,886 
   
 
 
    Suncoast Community Development District, Florida, Capital Improvement         
    Revenue Bonds, Series A, 5.875%, 5/01/34        2,625    2,398,568 
   
 
 
 
    Sunshine State Governmental Finance Commission, CP, 7.25%, 4/15/08    28,480    28,480,000 
   
 
 
    Tern Bay Community Development District, Florida, Capital Improvement         
    Revenue Refunding Bonds, Series B, 5%, 5/01/15        1,190    967,779 
   
 
 
 
    Tolomato Community Development District, Florida,             
    Special Assessment Bonds, 6.45%, 5/01/23        3,000    2,948,790 
   
 
 
 
    Watergrass Community Development District, Florida,             
    Special Assessment Revenue Bonds, Series B, 4.875%, 11/01/10    1,365    1,299,289 
   
 
 
                173,760,078 
 
 
 
 
Georgia - 3.0%    Atlanta, Georgia, Airport Passenger Facility Charge and Subordinate Lien         
    General Revenue Refunding Bonds, Series C, 5%, 1/01/33 (f)    17,000    16,855,670 
   
 
 
    Atlanta, Georgia, Tax Allocation Bonds (Atlantic Station Project),         
    7.90%, 12/01/11 (b)        5,000    5,953,900 
   
 
 
 
    Brunswick and Glynn County, Georgia, Development Authority, First Mortgage         
    Revenue Bonds (Coastal Community Retirement Corporation Project), Series         
    A, 7.125%, 1/01/25 (l)(m)        2,285    1,576,650 
   
 
 
 
    Brunswick and Glynn County, Georgia, Development Authority, First Mortgage         
    Revenue Bonds (Coastal Community Retirement Corporation Project), Series         
    A, 7.25%, 1/01/35 (l)(m)        4,555    3,142,950 
   
 
 
 
    College Park, Georgia, Business and IDA Revenue Bonds             
    (Civic Center Project), 5.75%, 9/01/10 (a)(b)        5,210    5,718,652 
   
 
 
 
    Fulton County, Georgia, Development Authority Revenue Bonds         
    (Morehouse College Project), 5.875%, 12/01/10 (a)(b)        3,450    3,788,548 
   
 
 
 
    Fulton County, Georgia, Residential Care Facilities, Revenue Refunding Bonds         
    (Canterbury Court Project), Series A, 6%, 2/15/22        2,250    2,142,067 
   
 
 
 
    Gainesville, Georgia, Redevelopment Authority, Educational Facilities         
    Revenue Refunding Bonds (Riverside Military Academy), 5.125%, 3/01/27    4,350    3,643,647 
   
 
 
    Gainesville, Georgia, Redevelopment Authority, Educational Facilities         
    Revenue Refunding Bonds (Riverside Military Academy), 5.125%, 3/01/37    1,800    1,416,870 
   
 
 

7

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)           Value 
 
 
 
 
    Milledgeville-Baldwin County, Georgia, Development Authority Revenue Bonds         
    (Georgia College and State University Foundation), 6%, 9/01/14 (b)    $ 1,500    $ 1,749,900 
   
 
 
    Rockdale County, Georgia, Development Authority Revenue Bonds         
    (Visy Paper Project), AMT, Series A, 6.125%, 1/01/34        5,000    4,614,450 
   
 
 
 
                50,603,304 
 
 
 
 
Illinois - 8.5%    Bolingbrook, Illinois, Special Services Area Number 1, Special Tax Bonds         
    (Forest City Project), 5.90%, 3/01/27        1,000    962,490 
   
 
 
 
    Chicago, Illinois, Board of Education, GO, VRDN, Series E-2,             
    7%, 3/01/26 (k)(n)        10,000    10,000,000 
   
 
 
 
    Chicago, Illinois, Motor Fuel Tax Revenue Bonds, Series A, 5%,         
    1/01/38 (o)        11,000    10,848,200 
   
 
 
 
    Chicago, Illinois, O'Hare International Airport, General Airport Revenue Bonds,         
    Third Lien, Series A, 5.25%, 1/01/23 (i)(o)        6,000    6,239,520 
   
 
 
 
    Chicago, Illinois, O'Hare International Airport Revenue Bonds, Third Lien,         
    AMT, Series B-2, 6%, 1/01/29 (j)        26,800    27,055,940 
   
 
 
 
    Chicago, Illinois, Park District, GO, Refunding, Series B, 5.75%, 1/01/15 (i)    350    373,583 
   
 
 
    Chicago, Illinois, Park District, Limited Tax, GO, Series A,             
    5.75%, 1/01/16 (i)        230    245,559 
   
 
 
 
    Chicago, Illinois, S/F Mortgage Revenue Bonds, AMT, Series A,         
    7.15%, 9/01/31 (c)(d)        280    290,150 
   
 
 
 
    Chicago, Illinois, Special Assessment Bonds (Lake Shore East),         
    6.75%, 12/01/32        2,000    2,013,580 
   
 
 
 
    Cicero, Illinois, GO, Refunding (Corporate Purpose), 6%, 12/01/28 (g)    3,210    3,367,065 
   
 
 
    Hodgkins, Illinois, Environmental Improvement Revenue Bonds (Metro Biosolids         
    Management LLC Project), AMT, 6%, 11/01/23        10,000    10,005,600 
   
 
 
 
    Illinois Development Finance Authority Revenue Bonds (Community         
    Rehabilitation Providers Facilities), Series A, 6.50%, 7/01/22    3,140    3,291,882 
   
 
 
    Illinois Municipal Electric Agency, Power Supply Revenue Bonds,         
    Series A, 5%, 2/01/35 (i)        10,000    9,655,600 
   
 
 
 
    Illinois State Finance Authority Revenue Bonds (Friendship Village of         
    Schaumburg), Series A, 5.625%, 2/15/37        1,750    1,473,413 
   
 
 
 
    Illinois State Finance Authority Revenue Bonds (Landing At Plymouth Place         
    Project), Series A, 6%, 5/15/37        2,155    1,927,475 
   
 
 
 
    Illinois State Finance Authority, Revenue Refunding Bonds (Advocate Health         
    and Hospital Corporation), VRDN, Series B-3, 6.50%, 11/01/38 (a)(k)    28,125    28,125,000 
   
 
 
    Illinois State Finance Authority, Revenue Refunding Bonds (Sherman Health         
    System Project), Series A, 5.50%, 8/01/37        3,500    3,214,505 
   
 
 
 
    Illinois State, GO, 1st Series, 5.75%, 12/01/15 (g)        8,890    9,479,851 
   
 
 
 
    Illinois State, GO, 1st Series, 5.75%, 12/01/16 (g)        3,745    3,994,454 
   
 
 
 
    Illinois State, GO, 1st Series, 5.75%, 12/01/17 (g)        4,000    4,266,440 
   
 
 
 
    Illinois State, Sales Tax Revenue Bonds, 6%, 6/15/20        3,000    3,160,290 
   
 
 
 
    Illinois State, Sales Tax Revenue Refunding Bonds, Series Q, 6%, 6/15/09    2,000    2,039,840 
   
 
 
    Village of Wheeling, Illinois, Revenue Bonds (North Milwaukee/Lake-Cook Tax         
    Increment Financing (TIF) Redevelopment Project), 6%, 1/01/25    1,585    1,438,594 
   
 
 
                143,469,031 
 
 
 
 
Indiana - 0.4%    Indiana Bond Bank, Special Program Revenue Bonds (Town of Westfield and         
    West Central Conservancy District Projects), Series A, 5.125%,         
    10/01/22 (g)        7,350    7,535,587 
 
 
 
 

8

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
Iowa - 0.3%    Iowa City, Iowa, Sewer Revenue Bonds, 5.75%, 7/01/21 (g)    $ 1,000     $1,001,790 
   
 
 
    Iowa Finance Authority, Health Care Facilities, Revenue Refunding Bonds         
    (Care Initiatives Project), 9.25%, 7/01/11 (b)        3,905    4,742,935 
   
 
 
 
                5,744,725 
 
 
 
 
Kansas - 0.6%    Sedgwick and Shawnee Counties, Kansas, S/F Mortgage Revenue         
    Bonds (Mortgage-Backed Securities Program), AMT, Series B-2,             
    5.25%, 12/01/38 (c)(d)        6,500    6,574,295 
   
 
 
 
    Sedgwick and Shawnee Counties, Kansas, S/F Revenue Bonds, AMT,         
    Series A-1, 6.95%, 6/01/29 (p)        1,300    1,372,865 
   
 
 
 
    Wichita, Kansas, Hospital Facilities Revenue Refunding and Improvement         
    Bonds, Series III, 6.25%, 11/15/19        2,500    2,679,725 
   
 
 
 
                10,626,885 
 
 
 
 
Louisiana - 1.5%    Jefferson Parish, Louisiana, Finance Authority, S/F Mortgage Revenue Bonds,         
    Series B, 5.70%, 12/01/48 (c)(d)        5,000    5,140,300 
   
 
 
 
    Louisiana HFA, S/F Mortgage Revenue Bonds, AMT, Series D-2,             
    5.80%, 6/01/20 (d)        275    278,311 
   
 
 
 
    Louisiana Local Government Environmental Facilities and Community         
    Development Authority Revenue Bonds (Capital Projects and Equipment         
    Acquisition Program), Series A, 6.30%, 7/01/30 (a)        7,000    7,330,260 
   
 
 
 
    Louisiana Local Government Environmental Facilities and Community         
    Development Authority Revenue Bonds (Westlake Chemical Corporation),         
    6.75%, 11/01/32        5,000    4,769,600 
   
 
 
 
    Louisiana Public Facilities Authority Revenue Bonds (University of New Orleans         
    Research and Technology Foundation, Inc. - Student Housing Project), 5.25%,         
    3/01/37 (g)        5,000    5,043,750 
   
 
 
 
    Rapides Finance Authority, Louisiana, Environmental Improvement Revenue         
    Bonds (International Paper Company Project), AMT, Series A, 6.55%,         
    11/15/23        2,000    2,028,680 
   
 
 
 
                24,590,901 
 
 
 
 
Maryland - 0.4%    Anne Arundel County, Maryland, Special Obligation Revenue Bonds (Arundel         
    Mills Project), 7.10%, 7/01/09 (b)        500    538,355 
   
 
 
 
    Maryland State Community Development Administration, Department of         
    Housing and Community Development, Housing Revenue Bonds, AMT,         
    Series B, 6.15%, 1/01/21        1,000    1,014,000 
   
 
 
 
    Maryland State Community Development Administration, Department of         
    Housing and Community Development Revenue Bonds (Waters Landing II         
    Apartments), AMT, Series A, 5.875%, 8/01/33        1,000    1,017,550 
   
 
 
 
    Maryland State Energy Financing Administration, Solid Waste Disposal Revenue         
    Bonds, Limited Obligation (Wheelabrator Water Projects), AMT, 6.45%,         
    12/01/16        1,000    1,011,640 
   
 
 
 
    Maryland State Health and Higher Educational Facilities Authority Revenue         
    Bonds (King Farm Presbyterian Community), Series B, 5%,             
    1/01/17        3,200    3,040,704 
   
 
 
 
                6,622,249 
 
 
 
 
Massachusetts -    Massachusetts Educational Financing Authority, Education Loan Revenue         
2.1%    Refunding Bonds, AMT, Issue E, 5.85%, 7/01/14 (a)        240    241,798 
   
 
 
 
    Massachusetts State Development Finance Agency Revenue Bonds (Linden         
    Ponds, Inc. Project), Series A, 5.50%, 11/15/27        3,000    2,589,360 
   
 
 
 

9

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    Massachusetts State Health and Educational Facilities Authority         
    Revenue Bonds (Medical Center of Central Massachusetts), CARS,         
    Series B, 7.22%, 6/23/22 (a)        $ 3,850    $ 3,984,673 
   
 
 
 
    Massachusetts State School Building Authority, Dedicated Sales Tax Revenue         
    Bonds, Series A, 5%, 8/15/37 (a)        26,415    26,452,773 
   
 
 
 
    Massachusetts State Water Pollution Abatement Trust, Water Abatement         
    Revenue Bonds, Series A, 6.375%, 2/01/15        130    130,437 
   
 
 
 
    Montachusett, Massachusetts, Regional Vocational Technical School District,         
    GO, 5.95%, 1/15/10 (b)(g)        1,600    1,682,000 
   
 
 
 
                35,081,041 
 
 
 
 
Michigan - 1.6%    Delta County, Michigan, Economic Development Corporation, Environmental         
    Improvement, Revenue Refunding Bonds             
    (Mead Westvaco-Escanaba), Series A, 6.25%, 4/15/12 (b)        7,500    8,435,175 
   
 
 
 
    Dickinson County, Michigan, Economic Development Corporation,         
    Environmental Improvement, Revenue Refunding Bonds             
    (International Paper Company Project), Series A, 5.75%, 6/01/16    500    507,155 
   
 
 
    Eastern Michigan University, General Revenue Refunding Bonds,         
    6%, 6/01/10 (a)(b)        585    635,649 
   
 
 
 
    Eastern Michigan University, General Revenue Refunding Bonds,         
    6%, 6/01/24 (a)        415    435,493 
   
 
 
 
    Flint, Michigan, Hospital Building Authority, Revenue Refunding Bonds (Hurley         
    Medical Center), 6%, 7/01/20        3,000    2,908,710 
   
 
 
 
    Macomb County, Michigan, Hospital Finance Authority, Hospital Revenue         
    Bonds (Mount Clemens General Hospital), Series B, 5.875%, 11/15/34    3,325    3,068,343 
   
 
 
    Michigan State Hospital Finance Authority, Revenue Refunding Bonds (Mercy-         
    Mount Clemens), Series A, 6%, 5/15/09 (b)(g)        1,500    1,584,360 
   
 
 
 
    Michigan Tobacco Settlement Financing Authority, Tobacco Settlement Asset-         
    Backed Revenue Bonds, Senior Series A, 6%, 6/01/48        10,000    9,130,800 
   
 
 
 
                26,705,685 
 
 
 
 
Minnesota - 0.5%    Anoka County, Minnesota, Solid Waste Disposal Revenue Bonds         
    (Natural Rural Utilities), AMT, Series A, 6.95%, 12/01/08        240    240,967 
   
 
 
 
    Eden Prairie, Minnesota, M/F Housing Revenue Bonds             
    (Rolling Hills Project), Series A, 6.15%, 8/20/31 (p)        1,000    1,057,190 
   
 
 
 
    Minneapolis and Saint Paul, Minnesota, Metropolitan Airports Commission,         
    Airport Revenue Bonds, AMT, Sub-Series D, 5.75%,             
    1/01/12 (i)        470    492,433 
   
 
 
 
    Minneapolis and Saint Paul, Minnesota, Metropolitan Airports Commission,         
    Airport Revenue Bonds, AMT, Sub-Series D, 5.75%,             
    1/01/14 (i)        470    488,330 
   
 
 
 
    Minneapolis and Saint Paul, Minnesota, Metropolitan Airports Commission,         
    Airport Revenue Bonds, AMT, Sub-Series D, 5.75%,             
    1/01/15 (i)        2,060    2,132,759 
   
 
 
 
    Ramsey County, Minnesota, Housing and Redevelopment Authority, M/F         
    Housing Revenue Bonds (Hanover Townhouses Project), AMT, 6%, 7/01/31    1,110    1,104,372 
   
 
 
    Saint Cloud, Minnesota, Health Care Revenue Refunding Bonds (Saint Cloud         
    Hospital Obligation Group), Series A, 6.25%, 5/01/20 (f)        1,000    1,063,850 
   
 
 
 
    Waconia, Minnesota, Health Care Facilities Revenue Bonds (Ridgeview Medical         
    Center Project), Series A, 6.125%, 1/01/10 (b)(e)        1,500    1,597,530 
   
 
 
 
                8,177,431 
 
 
 
 

10

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
Mississippi - 0.3%    Mississippi Home Corporation, S/F Mortgage Revenue Bonds, Series A-1, 5.50%,         
    6/01/38 (c)(d)        $ 3,905    $ 4,108,060 
   
 
 
 
    Warren County, Mississippi, Environmental Improvement Revenue Refunding         
    Bonds (International Paper Company Project), AMT, Series B,         
    6.75%, 8/01/21        1,700    1,737,196 
   
 
 
 
                5,845,256 
 
 
 
 
Missouri - 0.5%    Fenton, Missouri, Tax Increment Revenue Refunding and Improvement Bonds         
    (Gravois Bluffs Redevelopment Project), 5%, 4/01/14        1,000    1,047,440 
   
 
 
 
    Kansas City, Missouri, IDA, First Mortgage Health Facilities Revenue Bonds         
    (Bishop Spencer Place), Series A, 6.50%, 1/01/35        1,500    1,442,895 
   
 
 
 
    Missouri State Housing Development Commission, S/F Mortgage Revenue Bonds         
    (Homeownership Loan Program), AMT, Series E-1, 5.60%,             
    3/01/37 (d)        6,315    6,542,214 
   
 
 
 
                9,032,549 
 
 
 
 
Montana - 0.5%    Montana State Board of Housing, S/F Mortgage Revenue Refunding Bonds,         
    AMT, Series A-2, 5.50%, 6/01/37        2,925    3,023,660 
   
 
 
 
    Montana State Higher Education Student Assistance Corporation, Student Loan         
    Revenue Refunding Bonds, AMT, Sub-Series B, 6.40%, 12/01/32    6,000    6,063,480 
   
 
 
                9,087,140 
 
 
 
 
Nevada - 2.7%    Clark County, Nevada, Airport Revenue Bonds (Jet Aviation Fuel Tax), AMT,         
    Series C, 5.375%, 7/01/20 (a)        3,500    3,541,125 
   
 
 
 
    Clark County, Nevada, Improvement District Number 142,             
    Special Assessment Bonds, 6.375%, 8/01/23        1,520    1,427,964 
   
 
 
 
    Elko, Nevada, GO (Airport Improvement), AMT, Series B,             
    6.10%, 10/01/14 (g)        165    167,092 
   
 
 
 
    Elko, Nevada, GO (Airport Improvement), AMT, Series B,             
    6.30%, 10/01/19 (g)        245    247,683 
   
 
 
 
    Elko, Nevada, GO (Airport Improvement), AMT, Series B,             
    6.75%, 10/01/24 (g)        320    323,494 
   
 
 
 
    Elko, Nevada, GO (Airport Improvement), AMT, Series B, 7%, 10/01/29 (g)    225    227,459 
   
 
 
    Henderson, Nevada, Health Care Facilities, Revenue Refunding Bonds         
    (Catholic Healthcare West), Series B, 5.25%, 7/01/31        20,000    19,019,600 
   
 
 
 
    Reno, Nevada, Health Revenue Refunding Bonds (Catholic Healthcare West),         
    Series A, 5.25%, 7/01/31        10,000    9,509,800 
   
 
 
 
    Reno, Nevada, Special Assessment District Number 4 (Somerset Parkway),         
    6.625%, 12/01/22        1,850    1,857,826 
   
 
 
 
    Sparks, Nevada, Redevelopment Agency, Tax Allocation Revenue Refunding         
    Bonds, Series A, 6%, 1/15/15 (e)        3,110    3,274,364 
   
 
 
 
    Sparks, Nevada, Redevelopment Agency, Tax Allocation Revenue Refunding         
    Bonds, Series A, 6%, 1/15/23 (e)        6,315    6,432,333 
   
 
 
 
                46,028,740 
 
 
 
 
New Hampshire -    New Hampshire Health and Education Facilities Authority, Revenue Refunding         
0.2%    Bonds (Elliot Hospital), Series B, 5.60%, 10/01/22        1,750    1,788,150 
   
 
 
 
    New Hampshire Health and Education Facilities Authority, Revenue Refunding         
    Bonds (Havenwood-Heritage Heights Retirement Community), Series A, 5%,         
    1/01/16        540    491,546 
   
 
 
 

11

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    New Hampshire Health and Education Facilities Authority, Revenue Refunding         
    Bonds (Havenwood-Heritage Heights Retirement Community), Series A, 5.35%,         
    1/01/26        $ 1,035     $890,214 
   
 
 
 
                3,169,910 
 
 
 
 
New Jersey - 2.0%    Camden County, New Jersey, Pollution Control Financing Authority,         
    Solid Waste Resource Recovery, Revenue Refunding Bonds, AMT,         
    Series B, 7.50%, 12/01/09        195    195,554 
   
 
 
 
    New Jersey EDA, Retirement Community Revenue Bonds             
    (Cedar Crest Village Inc. Facility), Series A, 7.25%, 11/15/11 (b)    3,300    3,832,191 
   
 
 
    New Jersey EDA, State Lease Revenue Bonds (State Office Buildings Projects),         
    6%, 6/15/10 (a)(b)        3,680    3,971,456 
   
 
 
 
    New Jersey Health Care Facilities Financing Authority Revenue Bonds (South         
    Jersey Hospital), 6%, 7/01/12 (b)        3,130    3,508,542 
   
 
 
 
    New Jersey Health Care Facilities Financing Authority, Revenue Refunding         
    Bonds (Capital Health System Inc.), Series A, 5.75%, 7/01/23    2,250    2,280,240 
   
 
 
    New Jersey State Housing and Mortgage Finance Agency, M/F Housing Revenue         
    Refunding Bonds, Series B, 6.25%, 11/01/26 (f)        640    652,192 
   
 
 
 
    New Jersey State Turnpike Authority, Turnpike Revenue Refunding Bonds,         
    Series A, 5.75%, 1/01/10 (b)(g)        7,025    7,445,587 
   
 
 
 
    New Jersey State Turnpike Authority, Turnpike Revenue Refunding Bonds,         
    Series A, 5.75%, 1/01/18 (g)        2,975    3,071,628 
   
 
 
 
    Tobacco Settlement Financing Corporation of New Jersey, Asset-Backed         
    Revenue Bonds, 7%, 6/01/13 (b)        7,000    8,332,380 
   
 
 
 
                33,289,770 
 
 
 
 
New Mexico - 0.2%    New Mexico Mortgage Finance Authority, Revenue Refunding Bonds, Mortgage-         
    Backed Securities, Series F, 7%, 1/01/26 (d)        40    40,000 
   
 
 
 
    New Mexico Mortgage Financing Authority, S/F Mortgage Program Revenue         
    Bonds, AMT, Series D, 6.15%, 7/01/35 (c)(d)        2,865    3,006,416 
   
 
 
 
    Santa Fe County, New Mexico, Correctional System Revenue Bonds,         
    6%, 2/01/27 (f)        250    284,150 
   
 
 
 
                3,330,566 
 
 
 
 
New York - 5.2%    Metropolitan Transportation Authority, New York, Dedicated Tax Fund         
    Revenue Bonds, VRDN, Series D-2, 4.50%, 11/01/34 (a)(k)        10,000    10,000,000 
   
 
 
 
    Metropolitan Transportation Authority, New York, Revenue Bonds, GO, VRDN,         
    Sub-Series A-2, 7%, 11/01/34 (k)(n)        25,000    25,000,000 
   
 
 
 
    New York City, New York, City IDA, Civic Facility Revenue Bonds         
    (Special Needs Facilities Pooled Program), Series C-1, 6%, 7/01/12    3,230    3,202,384 
   
 
 
    New York City, New York, City IDA, Special Facility Revenue Bonds         
    (British Airways Plc Project), AMT, 7.625%, 12/01/32        4,050    4,147,200 
   
 
 
 
    New York City, New York, GO, Refunding, Series A, 6%, 5/15/10 (b)    6,540    7,096,946 
   
 
 
    New York City, New York, GO, Refunding, Series A, 6.25%, 5/15/10 (b)(j)    2,205    2,404,134 
   
 
 
    New York City, New York, GO, Refunding, Series A, 6%, 5/15/21 (j)    60    63,483 
   
 
 
    New York City, New York, GO, Series B, 5.875%, 8/01/10 (b)(g)    6,640    7,228,835 
   
 
 
    New York City, New York, GO, Series B, 5.875%, 8/01/15 (g)    1,300    1,391,871 
   
 
 
    New York State Dormitory Authority, Non-State Supported Debt, Revenue         
    Refunding Bonds (Mount Sinai-NYU Medical Center Health System), Series A,         
    6.50%, 7/01/10 (b)        590    647,419 
   
 
 
 

12

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    New York State Dormitory Authority, Non-State Supported Debt, Revenue         
    Refunding Bonds (Mount Sinai-NYU Medical Center Health System),         
    Series A, 6.50%, 7/01/16        $ 2,410    $ 2,519,414 
   
 
 
 
    New York State Dormitory Authority, Revenue Refunding Bonds         
    (Mount Sinai Health), Series A, 6.50%, 7/01/25        1,680    1,734,113 
   
 
 
 
    New York State Dormitory Authority, Revenue Refunding Bonds         
    (State University Educational Facilities), Series A, 7.50%, 5/15/13    3,000    3,600,150 
   
 
 
    New York State Environmental Facilities Corporation, State Clean Water and         
    Drinking Revenue Bonds (Revolving Funds), Series B, 5.875%, 1/15/19    1,360    1,418,031 
   
 
 
    Oneida County, New York, IDA Revenue Bonds (Civic Facility-Faxton Hospital),         
    Series C, 6.625%, 1/01/15 (e)        2,285    2,427,333 
   
 
 
 
    Suffolk County, New York, IDA, Civic Facility Revenue Bonds (Special Needs         
    Facilities Pooled Program), Series D-1, 6%, 7/01/12        95    94,062 
   
 
 
 
    Triborough Bridge and Tunnel Authority, New York, Subordinate Revenue         
    Bonds, 5.125%, 11/15/26 (a)        5,000    5,049,550 
   
 
 
 
    Westchester County, New York, IDA, Civic Facilities Revenue Bonds (Special         
    Needs Facilities Pooled Program), Series E-1, 6%, 7/01/12        705    698,042 
   
 
 
 
    Westchester County, New York, IDA, Continuing Care Retirement, Mortgage         
    Revenue Bonds (Kendal on Hudson Project), Series A,             
    6.50%, 1/01/13 (b)        8,095    9,228,543 
   
 
 
 
                87,951,510 
 
 
 
 
North Carolina -    Brunswick County, North Carolina, COP, 6%, 6/01/10 (b)(f)        920    1,000,058 
   
 
 
 
2.6%    North Carolina Eastern Municipal Power Agency, Power System Revenue         
    Bonds, Series D, 6.75%, 1/01/26        4,000    4,187,840 
   
 
 
 
    North Carolina Eastern Municipal Power Agency, Power System Revenue         
    Refunding Bonds, Series D, 6.70%, 1/01/19 (q)        4,440    4,660,180 
   
 
 
 
    North Carolina HFA, Home Ownership Revenue Bonds, AMT, Series 9-A,         
    5.80%, 1/01/20        3,850    3,983,865 
   
 
 
 
    North Carolina Medical Care Commission, Health Care Facilities,         
    First Mortgage Revenue Bonds (Presbyterian Homes Project),         
    6.875%, 10/01/10 (b)        2,500    2,769,900 
   
 
 
 
    North Carolina Medical Care Commission, Health Care Facilities, First         
    Mortgage Revenue Bonds (Presbyterian Homes Project), 5.50%, 10/01/31    3,000    2,741,940 
   
 
 
    North Carolina Medical Care Commission, Health Care Facilities,         
    First Mortgage Revenue Refunding Bonds (Presbyterian Homes Project),         
    Series B, 5.20%, 10/01/21        2,500    2,378,875 
   
 
 
 
    North Carolina Medical Care Commission, Health Care Facilities, First         
    Mortgage Revenue Refunding Bonds (Salemtowne Project), 5.10%,         
    10/01/30        1,100    941,897 
   
 
 
 
    North Carolina Medical Care Commission, Retirement Facilities, First Mortgage         
    Revenue Bonds (Forest at Duke Project), 6.375%, 9/01/12 (b)    1,625    1,834,235 
   
 
 
    North Carolina Medical Care Commission, Retirement Facilities, First         
    Mortgage Revenue Bonds (Givens Estates Project), Series A, 6.50%,         
    7/01/13 (b)        2,500    2,938,000 
   
 
 
 
    North Carolina Medical Care Commission, Retirement Facilities, First Mortgage         
    Revenue Refunding Bonds (Forest at Duke Project), 5.125%,             
    9/01/32        5,000    4,419,450 
   
 
 
 

13

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    North Carolina Medical Care Commission, Retirement Facilities, First Mortgage         
    Revenue Refunding Bonds (Givens Estates Project), 5%, 7/01/33    $ 1,000    $ 846,650 
   
 
 
    North Carolina Municipal Power Agency Number 1, Catawba Electric Revenue         
    Refunding Bonds, Series B, 6.375%, 1/01/13        500    531,815 
   
 
 
 
    North Carolina Municipal Power Agency Number 1, Catawba Electric Revenue         
    Refunding Bonds, Series B, 6.375%, 1/01/13 (q)        1,080    1,148,720 
   
 
 
 
    North Carolina Municipal Power Agency Number 1, Catawba Electric Revenue         
    Refunding Bonds, Series B, 6.50%, 1/01/20        5,000    5,259,000 
   
 
 
 
    North Carolina Municipal Power Agency Number 1, Catawba Electric Revenue         
    Refunding Bonds, Series B, 6.50%, 1/01/20 (q)        2,500    2,629,500 
   
 
 
 
    Piedmont Triad Airport Authority, North Carolina, Airport Revenue Refunding         
    Bonds, Series A, 6%, 7/01/09 (b)(f)        1,000    1,062,590 
   
 
 
 
    Piedmont Triad Airport Authority, North Carolina, Airport Revenue Refunding         
    Bonds, Series A, 6.375%, 7/01/09 (b)(f)        1,000    1,067,210 
   
 
 
 
                44,401,725 
 
 
 
 
Ohio - 2.2%    Buckeye Tobacco Settlement Financing Authority, Ohio, Tobacco Settlement         
    Asset-Backed Bonds, Series A-2, 6.50%, 6/01/47        23,000    22,217,770 
   
 
 
 
    Clark County, Ohio, Health Care Facilities, Revenue Refunding Bonds         
    (Ohio Masonic Home Project), VRDN, 6.75%, 10/01/25 (a)(k)        8,800    8,800,000 
   
 
 
 
    Ohio State, HFA, Mortgage Revenue Refunding Bonds, AMT, Series C, 5.90%,         
    9/01/35 (d)        5,170    5,378,868 
   
 
 
 
    Port of Greater Cincinnati Development Authority, Ohio,             
    Special Assessment Revenue Bonds (Cooperative Public             
    Parking Infrastructure Project), 6.40%, 2/15/34        1,470    1,405,585 
   
 
 
 
                37,802,223 
 
 
 
 
Oklahoma - 0.7%    Tulsa County, Oklahoma, Industrial Authority, Health Care Revenue Refunding         
    Bonds (Saint Francis Health System), 5%, 12/15/36        12,000    11,437,200 
 
 
 
 
Oregon - 0.3%    Forest Grove, Oregon, Campus Improvement Revenue Refunding Bonds         
    (Pacific University), 6%, 5/01/10 (b)(e)        250    268,652 
   
 
 
 
    Forest Grove, Oregon, Campus Improvement Revenue Refunding Bonds         
    (Pacific University), 6.20%, 5/01/10 (b)(e)        250    269,665 
   
 
 
 
    Oregon State Housing and Community Services Department,             
    Mortgage Revenue Refunding Bonds (S/F Mortgage Program),         
    AMT, Series A, 6.20%, 7/01/27        35    35,259 
   
 
 
 
    Oregon State Housing and Community Services Department,             
    Mortgage Revenue Refunding Bonds (S/F Mortgage Program),         
    Series A, 6.40%, 7/01/18        55    55,812 
   
 
 
 
    Portland, Oregon, M/F Housing Authority Revenue Bonds             
    (Lovejoy Station Apartments Project), AMT, 5.90%, 7/01/23 (g)    500    505,560 
   
 
 
    Portland, Oregon, Urban Renewal and Redevelopment Revenue Refunding         
    Bonds (Downtown Waterfront), Series A, 5.75%, 6/15/18 (a)        1,000    1,052,850 
   
 
 
 
    Portland, Oregon, Urban Renewal and Redevelopment Revenue Refunding         
    Bonds (South Park Blocks), Series A, 5.75%, 6/15/18 (a)        3,190    3,358,592 
   
 
 
 
                5,546,390 
 
 
 
 
Pennsylvania -    Allegheny County, Pennsylvania, IDA, Environmental Improvement Revenue         
3.9%    Refunding Bonds, 5.50%, 11/01/16        3,640    3,615,284 
   
 
 
 

14

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    Allegheny County, Pennsylvania, Sanitation Authority, Sewer Revenue Bonds,         
    5.75%, 12/01/10 (b)(g)        $ 2,220     $2,424,062 
   
 
 
 
    Bucks County, Pennsylvania, IDA, Retirement Community Revenue Bonds         
    (Ann's Choice Inc.), Series A, 6.125%, 1/01/25        1,760    1,716,651 
   
 
 
 
    Delaware County, Pennsylvania, IDA, Revenue Refunding Bonds         
    (Resource Recovery Facility), Series A, 6.10%, 7/01/13        7,750    7,802,700 
   
 
 
 
    Lancaster County, Pennsylvania, Hospital Authority Revenue Bonds (Brethren         
    Village Project), Series A, 6.25%, 7/01/26        1,160    1,130,327 
   
 
 
 
    Lancaster County, Pennsylvania, Hospital Authority Revenue Bonds (Brethren         
    Village Project), Series A, 6.50%, 7/01/40        1,000    969,730 
   
 
 
 
    Pennsylvania State Higher Educational Facilities Authority Revenue         
    Bonds (University of Pennsylvania Medical Center Health System),         
    Series A, 6%, 1/15/31        4,000    4,222,960 
   
 
 
 
    Philadelphia, Pennsylvania, Authority for IDR, Commercial Development,         
    7.75%, 12/01/17        1,265    1,266,227 
   
 
 
 
    Philadelphia, Pennsylvania, Redevelopment Authority Revenue Bonds         
    (Neighborhood Transformation), Series A, 5.30%, 4/15/26 (i)    36,210    36,641,623 
   
 
 
    Sayre, Pennsylvania, Health Care Facilities Authority, Revenue Refunding         
    Bonds (Guthrie Healthcare System), Series A, 5.875%, 12/01/11 (b)    3,915    4,366,908 
   
 
 
    Sayre, Pennsylvania, Health Care Facilities Authority, Revenue Refunding         
    Bonds (Guthrie Healthcare System), Series A, 5.875%, 12/01/31    1,085    1,100,342 
   
 
 
                65,256,814 
 
 
 
 
Rhode Island - 0.5% Rhode Island State Economic Development Corporation, Airport Revenue         
    Bonds, Series B, 6%, 7/01/10 (b)(i)        6,815    7,422,966 
   
 
 
 
    Rhode Island State Economic Development Corporation Revenue Bonds         
    (Providence Place Mall), 6.125%, 7/01/20 (e)        1,000    1,045,080 
   
 
 
 
                8,468,046 
 
 
 
 
South Carolina -    Medical University Hospital Authority, South Carolina, Hospital Facilities         
0.8%    Revenue Refunding Bonds, 6.50%, 8/15/12 (b)        2,450    2,808,337 
   
 
 
 
    Medical University Hospital Authority, South Carolina, Hospital Facilities         
    Revenue Refunding Bonds, Series A, 6.375%, 8/15/12 (b)        5,400    6,162,264 
   
 
 
 
    South Carolina Jobs EDA, Residential Care Facilities Revenue Bonds         
    (South Carolina Episcopal - Still Hopes Residence Project), Series A,         
    6.375%, 5/15/32        5,000    4,786,300 
   
 
 
 
                13,756,901 
 
 
 
 
Tennessee - 1.1%    Chattanooga, Tennessee, IDB, Lease Rent Revenue Bonds             
    (Southside Redevelopment Corporation), 5.75%, 10/01/17 (a)    4,485    4,756,029 
   
 
 
    Chattanooga, Tennessee, IDB, Lease Rent Revenue Bonds             
    (Southside Redevelopment Corporation), 5.75%, 10/01/18 (a)    3,740    3,920,567 
   
 
 
    Johnson City, Tennessee, Health and Educational Facilities Board, Retirement         
    Facility Revenue Bonds (Appalachian Christian Village Project), Series A,         
    6.25%, 2/15/32        1,000    936,530 
   
 
 
 
    Shelby County, Tennessee, Health, Educational and Housing Facility         
    Board, Hospital Revenue Refunding Bonds (Methodist Healthcare),         
    6.50%, 9/01/12 (b)        7,300    8,387,408 
   
 
 
 
                18,000,534 
 
 
 
 

15

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
Texas - 11.8%    Alliance Airport Authority, Inc., Texas, Special Facilities Revenue Refunding         
    Bonds (American Airlines Inc. Project), AMT, 5.75%, 12/01/29    $ 5,000    $ 3,374,100 
   
 
 
    Austin, Texas, Convention Center Revenue Bonds (Convention Enterprises         
    Inc.), First Tier, Series A, 6.60%, 1/01/11 (b)        5,300    5,836,625 
   
 
 
 
    Austin, Texas, Convention Center Revenue Bonds (Convention Enterprises         
    Inc.), First Tier, Series A, 6.70%, 1/01/11 (b)        2,300    2,538,924 
   
 
 
 
    Austin, Texas, Revenue Bonds (Town Lake Community Events Center Venue),         
    6.20%, 11/15/09 (b)(i)        10,630    11,333,706 
   
 
 
 
    Bexar County, Texas, Health Facilities Development Corporation, Revenue         
    Refunding Bonds (Army Retirement Residence Project), 6.125%,         
    7/01/12 (b)        600    681,348 
   
 
 
 
    Bexar County, Texas, Health Facilities Development Corporation, Revenue         
    Refunding Bonds (Army Retirement Residence Project), 6.30%,         
    7/01/12 (b)        1,750    1,999,427 
   
 
 
 
    Brazos River Authority, Texas, PCR, Refunding (TXU Energy Company Project),         
    AMT, Series C, 5.75%, 5/01/36        11,450    10,874,179 
   
 
 
 
    Brazos River Authority, Texas, Revenue Refunding Bonds (Reliant Energy Inc.         
    Project), Series B, 7.75%, 12/01/18        4,250    4,338,315 
   
 
 
 
    Brazos River, Texas, Harbor Navigation District, Brazoria County         
    Environmental Revenue Refunding Bonds (Dow Chemical Company Project),         
    AMT, Series A-7, 6.625%, 5/15/33        3,700    3,780,771 
   
 
 
 
    Central Texas Housing Finance Corporation, S/F Mortgage Revenue Bonds         
    (GNMA Mortgage Program), AMT, 8.20%, 6/28/17 (p)        370    386,872 
   
 
 
 
    Dallas-Fort Worth, Texas, International Airport Facility Improvement         
    Corporation, Revenue Bonds (Learjet Inc.), AMT, Series A-1, 6.15%,         
    1/01/16        3,620    3,439,941 
   
 
 
 
    Dallas-Fort Worth, Texas, International Airport Revenue Bonds, AMT,         
    Series A, 6%, 11/01/24 (i)        36,500    36,541,245 
   
 
 
 
    Gregg County, Texas, Health Facilities Development Corporation,         
    Hospital Revenue Bonds (Good Shepherd Medical Center Project),         
    6.375%, 10/01/10 (b)(e)        3,500    3,865,015 
   
 
 
 
    Gregg County, Texas, Health Facilities Development Corporation,         
    Hospital Revenue Bonds (Good Shepherd Medical Center Project),         
    6.875%, 10/01/10 (b)(e)        1,000    1,116,210 
   
 
 
 
    Gulf Coast Waste Disposal Authority, Texas, Revenue Refunding Bonds         
    (International Paper Company), AMT, Series A, 6.10%, 8/01/24    5,465    5,141,800 
   
 
 
    HFDC of Central Texas, Inc., Retirement Facilities Revenue Bonds,         
    Series A, 5.75%, 11/01/36        2,255    1,939,300 
   
 
 
 
    HFDC of Central Texas, Inc., Retirement Facilities Revenue Bonds         
    (Village at Gleannloch Farms), Series A, 5.50%, 2/15/37        1,850    1,525,436 
   
 
 
 
    Houston, Texas, Airport System, Special Facilities Revenue Bonds (Continental         
    Airlines), AMT, Series E, 7%, 7/01/29        6,000    5,825,100 
   
 
 
 
    Kerrville, Texas, Health Facilities Development Corporation, Hospital Revenue         
    Bonds (Sid Peterson Memorial Hospital Project), 5.25%, 8/15/21    4,000    3,858,240 
   
 
 
    Matagorda County, Texas, Navigation District Number 1, Revenue Refunding         
    Bonds (Reliant Energy Inc.), Series C, 8%, 5/01/29        8,080    8,249,195 
   
 
 
 
    Matagorda County, Texas, Port of Bay City Authority Revenue Bonds (Hoechst         
    Celanese Corp. Project), AMT, 6.50%, 5/01/26        7,350    6,781,478 

16

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
    Red River, Texas, Education Finance Revenue Bonds (Saint Mark's School-         
    Texas Project), 6%, 2/15/10 (b)        $ 1,000    $ 1,066,920 
   
 
 
 
    South Plains, Texas, Housing Finance Corporation, S/F Mortgage Revenue         
    Bonds, AMT, Series A, 7.30%, 9/01/31 (d)        770    783,598 
   
 
 
 
    Southeast Texas Housing Finance Corporation, Revenue Bonds, AMT,         
    Series B, 8.50%, 11/01/25 (c)(p)        120    122,621 
   
 
 
 
    Tarrant County, Texas, Cultural Education Facilities Financing Corporation,         
    Retirement Facilities Revenue Refunding Bonds (Northwest Senior Housing -         
    Edgemere Project), Series A, 6%, 11/15/26        2,200    2,137,432 
   
 
 
 
    Tarrant County, Texas, Cultural Education Facilities Financing Corporation,         
    Retirement Facilities Revenue Refunding Bonds (Northwest Senior Housing -         
    Edgemere Project), Series A, 6%, 11/15/36        3,000    2,831,910 
   
 
 
 
    Texas State Affordable Housing Corporation, S/F Mortgage Revenue Bonds         
    (Fire Fighter and Law Enforcement or Security Officer Home Loan Program),         
    AMT, Series C, 5.45%, 12/01/39 (c)(d)        4,960    4,902,486 
   
 
 
 
    Texas State Affordable Housing Corporation, S/F Mortgage Revenue Bonds         
    (Professional Educators Home Loan Program), AMT, Series A-1, 5.50%,         
    12/01/39 (c)(d)        6,205    6,162,242 
   
 
 
 
    Texas State Public Finance Authority, Building Revenue Bonds (General         
    Services Commission Project), Series A, 6%, 2/01/10 (b)(f)        2,100    2,239,020 
   
 
 
 
    Texas State Public Finance Authority, Building Revenue Bonds (State         
    Preservation Project), Series B, 6%, 8/01/09 (b)(f)        1,000    1,055,100 
   
 
 
 
    Texas State Turnpike Authority, Central Texas Turnpike System Revenue         
    Bonds, First Tier, Series A, 5.75%, 8/15/38 (a)        45,000    46,414,800 
   
 
 
 
    Upper Trinity Regional Water District, Texas, Water Revenue Bonds (Regional         
    Treated Water Supply System), Series A, 6%, 8/01/10 (b)(i)        4,930    5,334,408 
   
 
 
 
    Webster, Texas, GO, COP, Series A, 6%, 3/01/10 (b)(f)        1,500    1,603,455 
   
 
 
 
    Webster, Texas, GO, COP, Series A, 6%, 3/01/21 (f)        805    842,730 
   
 
 
 
    West Central Texas Regional Housing Finance Corporation, S/F Mortgage         
    Revenue Bonds (Mortgage-Backed Securities Program), AMT, Series A, 5.35%,         
    12/01/39 (c)(d)        1,234    1,210,491 
   
 
 
 
                200,134,440 
 
 
 
 
Utah - 0.0%    Utah State, HFA, S/F Mortgage Revenue Refunding Bonds, AMT, Series C, Class         
    III, 5.50%, 1/01/18        700    717,269 
 
 
 
 
Vermont - 0.6%    Vermont State Student Assistance Corporation, Education Loan Revenue         
    Bonds, SAVRS, VRDN, AMT, Series N, 7.363%, 12/15/32 (a)(k)    10,000    9,500,000 
 
 
 
Virginia - 0.7%    Albemarle County, Virginia, IDA, Residential Care Facilities, Mortgage         
    Revenue Refunding Bonds (Westminster-Canterbury), 5%, 1/01/24    2,750    2,498,127 
   
 
 
    Chesterfield County, Virginia, IDA, PCR, Refunding (Virginia Electric and         
    Power Company), Series B, 5.875%, 6/01/17        2,425    2,569,433 
   
 
 
 
    Fairfax County, Virginia, EDA, Residential Care Facilities, Mortgage Revenue         
    Refunding Bonds (Goodwin House, Inc.), 5.125%, 10/01/37        3,250    2,858,895 
   
 
 
 
    Norfolk, Virginia, Redevelopment and Housing Authority, First Mortgage         
    Revenue Bonds (Retirement Community), Series A, 6%, 1/01/25    500    476,120 
   
 
 
    Norfolk, Virginia, Redevelopment and Housing Authority, First Mortgage         
    Revenue Bonds (Retirement Community), Series A, 6.125%, 1/01/35    1,100    1,033,978 
   
 
 
    Watkins Centre Community Development Authority, Virginia,         
    Revenue Bonds, 5.40%, 3/01/20        2,500    2,258,800 
   
 
 
 
                11,695,353 
 
 
 
 

17

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds        (000)    Value 
 
 
 
 
Washington - 1.8%    Central Puget Sound Regional Transportation Authority, Washington,         
    Sales and Use Tax Revenue Bonds, Series A, 5%, 11/01/34        $ 15,000    $ 15,033,300 
   
 
 
 
    Central Puget Sound Regional Transportation Authority, Washington,         
    Sales and Use Tax Revenue Bonds, Series A, 5%, 11/01/36        5,000    5,007,350 
   
 
 
 
    Port of Seattle, Washington, Special Facilities Revenue Bonds, Series A, 6%,         
    3/01/10 (b)(g)        3,000    3,235,620 
   
 
 
 
    Seattle, Washington, Housing Authority Revenue Bonds (Newholly Project),         
    AMT, 6.25%, 12/01/35        2,750    2,707,045 
   
 
 
 
    Seattle, Washington, Housing Authority Revenue Bonds (Replacement Housing         
    Project), 6.125%, 12/01/32        4,620    4,490,825 
   
 
 
 
                30,474,140 
 
 
 
 
Wisconsin - 0.7%    Wisconsin Housing and EDA, Home Ownership Revenue Bonds, AMT,         
    Series C, 6%, 9/01/36        885    923,905 
   
 
 
 
    Wisconsin State, GO, AMT, Series B, 6.20%, 11/01/26 (g)        1,960    1,989,831 
   
 
 
 
    Wisconsin State Health and Educational Facilities Authority Revenue Bonds         
    (SynergyHealth Inc.), 6%, 11/15/23        5,655    5,697,978 
   
 
 
 
    Wisconsin State Health and Educational Facilities Authority Revenue Bonds         
    (SynergyHealth Inc.), 6%, 11/15/32        3,700    3,561,731 
   
 
 
 
                12,173,445 
 
 
 
 
Puerto Rico - 0.8%    Puerto Rico Commonwealth Highway and Transportation Authority,         
    Transportation Revenue Bonds, 5.75%, 7/01/22        8,045    8,241,539 
   
 
 
 
    Puerto Rico Commonwealth Infrastructure Financing Authority, Special Tax         
    and Capital Appreciation Revenue Bonds, Series A, 4.917%,             
    7/01/30 (i)(m)        19,500    5,197,335 
   
 
 
 
    Puerto Rico Commonwealth, Public Improvement, GO, Refunding, 5.70%,         
    7/01/20 (g)        785    806,423 
   
 
 
 
                14,245,297 
 
 
 
 
U.S.    Virgin Islands Government Refinery Facilities, Revenue Refunding Bonds         
Virgin Islands -    (Hovensa Coker Project), AMT, 6.50%, 7/01/21        8,000    8,172,160 
0.5%                 
 
 
 
 
    Total Municipal Bonds (Cost - $1,542,438,380) - 90.5%            1,532,921,193 
 
 
 
 
    Municipal Bonds Transferred to Tender Option Bond Trusts (r)         
 
 
 
Florida - 2.0%    Lee County, Florida, Airport Revenue Bonds, AMT, Series A,             
    6%, 10/01/29 (f)        14,000    14,203,560 
   
 
 
 
    Port St. Lucie, Florida, Utility Revenue Bonds, 5.125%, 9/01/36 (g)    20,115    20,069,339 
   
 
 
                34,272,899 
 
 
 
 
Michigan - 0.8%    Hartland, Michigan, Consolidated School District, GO, Refunding,         
    5.125%, 5/01/29        13,500    13,558,590 
 
 
 
 
New Jersey - 1.4%    New Jersey EDA, School Facilities Construction Revenue Bonds, Series O,         
    5.25%, 3/01/24        22,000    22,930,820 
 
 
 
 
Texas - 2.1%    Houston, Texas, Airport System Revenue Refunding Bonds, Sub-Lien,         
    AMT, Series A, 5.50%, 7/01/23 (f)        15,000    15,102,600 
   
 
 
 
    Houston, Texas, Combined Utility System, First Lien Revenue Refunding         
    Bonds, Series A, 5.125%, 5/15/28 (g)        20,000    20,108,400 
   
 
 
 
                35,211,000 
 
 
 
 
Puerto Rico - 0.5%    Puerto Rico Industrial Tourist Educational, Medical and Environmental Control         
    Facilities Revenue Bonds (Hospital de la Concepcion), Series A, 6.125%,         
    11/15/25        4,000    4,231,840 
   
 
 
 

18

BlackRock Municipal Bond Fund, Inc. - BlackRock National Municipal Fund

Schedule of Investments as of March 31, 2008 (Unaudited)    (Percentages shown are based on Net Assets) 
 
            Par     
State    Municipal Bonds Transferred to Tender Option Bond Trusts (r)    (000)       Value 
 
 
 
    Puerto Rico Industrial Tourist Educational, Medical and Environmental         
    Control Facilities Revenue Bonds (Hospital de la Concepcion), Series A,         
    6.125%, 11/15/30        $ 4,220        $  4,396,143 
 
 
 
 
                8,627,983 
 
 
 
 
    Total Municipal Bonds Transferred to Tender Option Bond Trusts         
    (Cost - $116,829,298) - 6.8%            114,601,292 
 
 
 
 
    Short-Term Securities        Shares     
 
 
 
 
    Merrill Lynch Institutional Tax-Exempt Fund, 2.16% (s)(t)        75,923,245    75,923,245 
 
 
 
 
    Total Short-Term Securities (Cost - $75,923,245) - 4.5%            75,923,245 
 
 
 
 
    Total Investments (Cost - $1,735,190,923*) - 101.8%            1,723,445,730 
    Other Assets Less Liabilities - 1.7%            28,661,439 
    Liability for Trust Certificates, Including Interest             
    Expense Payable - (3.5%)            (59,110,724) 
           
 
    Net Assets - 100.0%        $ 1,692,996,445 
           

* The cost and unrealized appreciation (depreciation) of investments as of March 31, 2008, as computed for federal income tax purposes, were as follows:

Aggregate cost    $ 1,678,330,062 
   
Gross unrealized appreciation    $ 31,173,533 
Gross unrealized depreciation    (44,761,508) 
   
Net unrealized depreciation    $ (13,587,975) 
   

(a)      AMBAC Insured.
 
(b)      U.S. government securities, held in escrow, are used to pay interest on this security, as well as, retire the bond in full, at the date indicated, typically at a premium to par.
 
(c)      FHLMC Collateralized.
 
(d)      FNMA/GNMA Collateralized.
 
(e)      Radian Insured.
 
(f)      FSA Insured.
 
(g)      MBIA Insured.
 
(h)      FHA Insured.
 
(i)      FGIC Insured.
 
(j)      XL Capital Insured.
 
(k)      Variable rate security. Rate shown is as of report date.
 
(l)      Non-income producing security; issuer filed for bankruptcy or is in default of interest payments.
 
(m)      Represents a zero coupon bond; the interest rate shown reflects the effective yield at the time of purchase.
 
(n)      CIFG Insured.
 
(o)      Assured Guaranty Insured.
 
(p)      GNMA Collateralized.
 
(q)      ACA Insured.
 
(r)      Securities represent underlying bonds transferred to a separate securitization trust established in a tender option bond transaction which the Fund may have acquired the residual interest certificates. These securities serve as collateral in a financing transaction.
 
(s)      Investments in companies considered to be an affiliate of the Fund, for purposes of Section 2(a)(3) of the Investment Company Act of 1940, were as follows:
 
    Net     
     Affiliate    Activity    Dividend Income 
 
 
     Merrill Lynch Institutional Tax-Exempt Fund    47,317,267    $1,116,633 
 
 
(t) Represents the current yield as of report date.         

19

Item 2 – Controls and Procedures

2(a) – The registrant’s principal executive and principal financial officers or persons performing
similar functions have concluded that the registrant’s disclosure controls and procedures (as
defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the
“1940 Act”)) are effective as of a date within 90 days of the filing of this report based on the
evaluation of these controls and procedures required by Rule 30a-3(b) under the 1940 Act
and Rule 15d-15(b) under the Securities Exchange Act of 1934, as amended.

2(b) – There were no changes in the registrant’s internal control over financial reporting (as
defined in Rule 30a-3(d) under the 1940 Act) that occurred during the registrant’s last fiscal
quarter that have materially affected, or are reasonably likely to materially affect, the
registrant’s internal control over financial reporting.

Item 3 – Exhibits

Certifications – Attached hereto

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment
Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by
the undersigned, thereunto duly authorized.

BlackRock Municipal Bond Fund, Inc.

By: /s/ Donald C. Burke
Donald C. Burke
Chief Executive Officer (principal executive officer) of
BlackRock Municipal Bond Fund, Inc.

Date: May 22, 2008

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment
Company Act of 1940, this report has been signed below by the following persons on behalf
of the registrant and in the capacities and on the dates indicated.

By: /s/ Donald C. Burke
Donald C. Burke
Chief Executive Officer (principal executive officer) of
BlackRock Municipal Bond Fund, Inc.

Date: May 22, 2008

By: /s/ Neal J. Andrews
Neal J. Andrews
Chief Financial Officer (principal financial officer) of
BlackRock Municipal Bond Fund, Inc.

Date: May 22, 2008