Exhibit 21.1

Entity Name	State of Organization
101 Carnegie Center Associates		New Jersey
125 West 55th Street Venture Liquidating Trust		Delaware
17M Associates		District of Columbia
191 Spring Street Trust		Massachusetts
2 GCT Partners LLC		Delaware
2 GCT Venture LLC		Delaware
206 Associates Limited Partnership		New Jersey
210 Associates Limited Partnership		New Jersey
211 Associates Limited Partnership		New Jersey
30 Shattuck Road LLC		Delaware
399 Services LLC		Delaware
40-46 Harvard Street Trust		Massachusetts
500 North Capitol LLC		Delaware
500 North Capitol Venture LLC		Delaware
540 Land Partners LLC		Delaware
540 Madison Partners LLC		Delaware
540 Madison Venture LLC		Delaware
635 Mass Ave LLC		Delaware
738 Eighth Avenue LLC		Delaware
767 Fifth Junior Mezz LLC		Delaware
767 Fifth Lender LLC		Delaware
767 Fifth Partners LLC		Delaware
767 Fifth Senior Mezz LLC		Delaware
767 Fifth TRS LLC		Delaware
767 Venture, LLC		Delaware
90 Church Street Limited Partnership		Delaware
901 New York Avenue Fitness Center LLC		Delaware
901 New York LLC		Delaware
901 New York REIT LLC		Delaware
91 Hartwell Avenue Trust		Massachusetts
92 Hayden Avenue Trust		Massachusetts
AJ Lot 2R Financing LLC		Delaware
AJ Lot 2R LLC		Delaware
AJ Lot 3R Financing LLC		Delaware
AJ Lot 3R LLC		Delaware
AJ Lot 4R Financing LLC		Delaware
AJ Lot 4R LLC		Delaware
AJ Lot 6 Financing LLC		Delaware
AJ Lot 6 LLC		Delaware
AJ Lot 7R LLC		Delaware
Annapolis Junction NFM LLC		Delaware
Big Apple Associates Limited Partnership		Delaware
Block 4 LLC		Delaware
Boston Properties Limited Partnership		Delaware
Boston Properties LLC		Delaware
Boston Properties Management LLC		Delaware
Boston Properties Management, Inc.		Delaware
Boston Properties TRS, Inc.		Delaware
BP 103 Fourth Avenue LLC		Delaware
BP 111 Huntington Ave LLC		Delaware

Entity Name	State of Organization
BP 125 West 55th Street LLC		Delaware
BP 1330 Connecticut Avenue LLC		Delaware
BP 1333 New Hampshire Avenue LLC		Delaware
BP 140 Kendrick Street Cafe LLC		Delaware
BP 140 Kendrick Street LLC		Delaware
BP 140 Kendrick Street Property LLC		Delaware
BP 2 GCT LLC		Delaware
BP 20 F Street Limited Partnership		Delaware
BP 201 Spring Street LLC		Delaware
BP 230 City Point Cafe LLC		Delaware
BP 303 Almaden Associates LLC		Delaware
BP 399 Park Avenue LLC		Delaware
BP 500 North Capitol LLC		Delaware
BP 510 Madison Ave LLC		Delaware
BP 510 Madison HC LLC		Delaware
BP 510 Madison LLC		Delaware
BP 540 Madison LLC		Delaware
BP 599 Lexington Avenue LLC		Delaware
BP 767 Fifth LLC		Delaware
BP 888 Boylston LLC		Delaware
BP 99 Third Avenue LLC		Delaware
BP Almaden Associates LLC		Delaware
BP Atlantic Wharf Master Tenant LLC		Delaware
BP AW Garage LLC		Delaware
BP AW Retail LLC		Delaware
BP AW Tower Office LLC		Delaware
BP AW Waterfront Office LLC		Delaware
BP AWRR Trustee I LLC		Delaware
BP AWRR Trustee II LLC		Delaware
BP AWTO Trustee I LLC		Delaware
BP AWTO Trustee II LLC		Delaware
BP AWTO Trustee III LLC		Delaware
BP Bay Colony Cafe LLC		Delaware
BP Bay Colony HC LLC		Delaware
BP Bay Colony Holdings LLC		Delaware
BP Bay Colony LLC		Delaware
BP Bedford Street Cafe LLC		Delaware
BP Belvidere LLC		Delaware
BP Cambridge Center Residential LLC		Delaware
BP Crane Meadow, L.L.C.		Delaware
BP East Garage LLC		Delaware
BP EC1 Holdings LLC		Delaware
BP EC2 Holdings LLC		Delaware
BP EC3 Holdings LLC		Delaware
BP EC4 Holdings LLC		Delaware
BP Federal Street LLC		Delaware
BP Five CC LLC		Delaware
BP Four CC LLC		Delaware
BP Fourth Avenue Cafe LLC		Delaware
BP Fourth Avenue, LLC		Delaware
BP Hancock LLC		Delaware
BP Hancock Parking LLC		Delaware

Entity Name	State of Organization
BP Hartwell Avenue Cafe LLC		Delaware
BP Hayden Avenue Cafe LLC		Delaware
BP Hotel LLC		Delaware
BP II LLC		Delaware
BP III LLC		Delaware
BP Jones Road Cafe LLC		Delaware
BP Kingstowne Office Building K LLC		Delaware
BP Kingstowne Office Building T LLC		Delaware
BP Kingstowne Theatre LLC		Delaware
BP LOP LLC		Delaware
BP Mall Road Cafe LLC		Delaware
BP Management Sub LLC		Delaware
BP Management, L.P.		Delaware
BP Market Square North GP LLC		Delaware
BP Mill Road Cafe LLC		Delaware
BP New Dominion Technology Park II LLC		Delaware
BP New York LLC		Delaware
BP Prospect Place LLC		Delaware
BP Prucenter Acquisition LLC		Delaware
BP Prucenter Development LLC		Delaware
BP Prucenter Exeter LLC		Delaware
BP Prucenter Fairfield LLC		Delaware
BP RB Developer LLC		Delaware
BP Realty New Jersey LLC		New Jersey
BP Realty Washington LLC		Delaware
BP Reservoir Place Cafe LLC		Delaware
BP Reservoir Place LLC		Delaware
BP Reston Eastgate LLC		Delaware
BP RTC Member LLC		Delaware
BP Russia Building LLC		Delaware
BP Russia Wharf LLC		Delaware
BP Services TRS LLC		Delaware
BP Seven Cambridge Center LLC		Delaware
BP Seventeen Cambridge Center LLC		Delaware
BP Spring Street Cafe LLC		Delaware
BP Supermarket LLC		Delaware
BP Third Avenue LLC		Delaware
BP Times Square Tower Mezzanine LLC		Delaware
BP West Street Cafe LLC		Delaware
BP Weston Quarry LLC		Delaware
BP/CGCenter I LLC		Delaware
BP/CGCenter II LLC		Delaware
BP/CGCenter MM LLC		Delaware
BP/CRF 901 New York Avenue LLC		Delaware
BP/CRF Metropolitan Square LLC		Delaware
BP/DC 767 Fifth LLC		Delaware
BP/DC Properties, Inc.		Maryland
BP/DC REIT LLC		Delaware
BP-AJ LLC		Delaware
BPI EC4 LLC		Delaware
BPNS Garage General LLC		Delaware
BPNS Garage Limited LLC		Delaware

Entity Name	State of Organization
BPNS Hotel General LLC		Delaware
BPNS Hotel Limited LLC		Delaware
BPNS Office General LLC		Delaware
BPNS Office Limited LLC		Delaware
BPNS Podium General LLC		Delaware
BPNS Podium Limited LLC		Delaware
BPNS Residential General LLC		Delaware
BPNS Residential Limited LLC		Delaware
BP-WP Project Developer Manager LLC		Delaware
BXP 601 & 651 Gateway Center LP		Delaware
BXP 611 Gateway Center LP		Delaware
BXP California GP LLC		Delaware
BXP Folsom Holding LLC		Delaware
BXP Folsom-Hawthorne LLC		Delaware
BXP Mission 535 LLC		Delaware
BXP North First LP		Delaware
BXP Ravendale LP		Delaware
BXP Research Park LP		Delaware
BXP TB Development LLC		Delaware
BXP Technology Park LP		Delaware
BXP Transbay Management LLC		Delaware
BXP West El Camino LP		Delaware
BXP Zanker Road LP		Delaware
Cambridge Center North Trust		Massachusetts
Cambridge Center West Garage LLC		Delaware
Cambridge Center West Trust		Massachusetts
Carnegie 214 Associates Limited Partnership		New Jersey
Carnegie 504 Associates		New Jersey
Carnegie 506 Associates		New Jersey
Carnegie 508 Associates		New Jersey
Carnegie 510 Associates, L.L.C.		Delaware
Carnegie 804 Associates, LLC		Delaware
Carnegie Center Associates		New Jersey
CRF Met Square, LLC		Delaware
Discovery Square, L.L.C.		Delaware
Downtown Boston Properties Trust		Massachusetts
Elandzee Trust		Massachusetts
Eleven Cambridge Center Trust		Massachusetts
Embarcadero Center Associates		California
Embarcadero Center, Inc.		California
Four Embarcadero Center Venture		California
Fourteen Cambridge Center Trust		Massachusetts
Gateway Center LLC		Delaware
Gladden Properties LLC		Delaware
Hayden Office Trust		Massachusetts
IXP, LLC		Vermont
Jones Road Development Associates LLC		Delaware
KEG Associates I, LLC		Delaware
Lexreal Associates Limited Partnership		New York
LKE BP Fourth Avenue Limited Partnership		Massachusetts
Mall Road Trust		Massachusetts
Market Square North Associates Limited Partnership		Delaware

Entity Name	State of Organization
Market Square North Fitness Center LLC		Delaware
MBZ-Lex Trust		Massachusetts
Metropolitan Square REIT LLC		Delaware
MGA Virginia 85-1 Limited Partnership		Virginia
MGA Virginia 86-1 Limited Partnership		Virginia
MGA Virginia 86-2 Limited Partnership		Virginia
Montgomery Village Avenue Joint Venture Limited Partnership		Maryland
Montgomery Village GP LLC		Delaware
Montvale LLC		Maryland
New Dominion Technology Corp.		Delaware
New Dominion Technology Park II LLC		Delaware
New Dominion Technology Park LLC		Delaware
No. 1 Times Square Development LLC		Delaware
No. 5 Times Square Development LLC		Delaware
NY 510 Junior Mezz Lender LLC		Delaware
NYXP, LLC		Vermont
Ocean View Development Company Limited Partnership		District of Columbia
One Cambridge Center Trust		Massachusetts
One Embarcadero Center Venture		California
One Freedom Square, L.L.C.		Delaware
Princeton 202 Associates Limited Partnership		New Jersey
Princeton Childcare Associates Limited Partnership		New Jersey
RBP 45th Associates LLC		New York
RBP Joint Venture LLC		New York
Reston Corporate Center Limited Partnership		Virginia
Reston Streets LLC		Delaware
Reston Town Center JV LLC		Delaware
Reston Town Center Office Park Phase One Limited Partnership		Virginia
Reston Town Center Property LLC		Delaware
Reston VA 939, L.L.C.		Delaware
RTC Gift Card LLC		Delaware
Russia Building TRS LLC		Delaware
School Street Associates Limited Partnership		District of Columbia
SCV Partners		New Jersey
South of Market Garage LLC		Delaware
South of Market LLC		Delaware
South of Market Lot 16 LLC		Delaware
Springfield 6601 LLC		Delaware
Springfield Metro Center II, LLC		Delaware
Springfield Parcel C LLC		Delaware
Square 36 Office Joint Venture		District of Columbia
Square 407 Limited Partnership		District of Columbia
Square 54 Office Fitness TRS LLC		Delaware
Square 54 Office Owner LLC		Delaware
Square 54 Residential Owner LLC		Delaware
Stony Brook Associates LLC		Delaware
Ten Cambridge Center Trust		Massachusetts
The Atlantic Monthly Trust		Massachusetts
The Double B Partnership		Massachusetts
The Double B Trust		Massachusetts
The Metropolitan Square Associates LLC		District of Columbia
Three Cambridge Center Trust		Massachusetts

Entity Name	State of Organization
Three Embarcadero Center Venture		California
Times Square Tower Associates LLC		Delaware
Tower Oaks Financing LLC		Delaware
Tracer Lane Trust II		Massachusetts
Transbay Tower Holdings LLC		Delaware
Transbay Tower LLC		Delaware
Two Cambridge Center Trust		Massachusetts
Two Freedom Square, L.L.C.		Delaware
Washingtonian North Associates Limited Partnership		Maryland
Wisconsin Place Office LLC		Delaware
Wisconsin Place Office Manager LLC		Delaware
WP Project Developer LLC		Delaware
WP Trust		Massachusetts
Zee Bee Trust II		Massachusetts
Zee Em Trust II		Massachusetts