FIXED INCOME LIQUIDITY EQUITIES ALTERNATIVES BLACKROCK SOLUTIONS

BlackRock Funds

Exchange Portfolio

BlackRock Shares

Prospectus

January 31, 2005

BlackRock Funds^SM is a mutual fund family with 50 investment portfolios, 1 of which is described in this prospectus.

NOT FDIC INSURED MAY LOSE VALUE NO BANK GUARANTEE The Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

Table of

Contents

How to Find the Information You Need How to Find the Information You Need	1
Exchange	2
About Your Investments How to Buy/Sell Shares	7
Dividends/Distributions/Taxes	13

How to Find the

Information You Need

About BlackRock Funds

This is the BlackRock Exchange Portfolio Prospectus. It has been written to provide you with the information you need to make an informed decision about whether to invest in BlackRock Funds (the Company). Also included are sections that tell you about buying and selling shares, certain fees and expenses, shareholder features of the fund and your rights as a shareholder.

BlackRock, Inc., the parent of BlackRock Advisors, Inc. (BlackRock), the funds’ investment adviser, recently acquired SSRM Holdings, Inc., the parent of State Street Research & Management Company, the investment adviser to the former State Street Research mutual funds. In connection with the transaction, the State Street Research mutual funds were combined with certain BlackRock funds, including the Exchange Portfolio.

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BlackRock

Exchange Portfolio

IMPORTANT DEFINITIONS

Equity Security: A security, such as stock, representing ownership of a company. Bonds, in comparison, are referred to as fixed income or debt securities because they represent indebtedness to the bondholders, not ownership (although convertible bonds are fixed income securities that are convertible to equity according to their terms).

Investment Style: Refers to the guiding principles of a mutual fund’s investment choices. The investment style of this fund is growth, referring to the type of securities the manager will choose for this fund.

Growth Companies: All stocks are generally divided into the categories of “growth” or “value,” although there are times when a growth fund and value fund may own the same stock. Growth stocks are companies whose earnings growth potential appears to the manager to be greater than the market in general and whose revenue growth is expected to continue for an extended period. These stocks typically pay relatively low dividends and sell at relatively high valuations. Value stocks are companies that appear to the manager to be undervalued by the market as measured by certain financial formulas.

Shares of the fund are not currently offered to the public.

Investment Goal

The fund seeks long-term growth of capital and consequent long-term growth of income.

Primary Investment Strategies

In pursuit of this goal, the fund normally invests largely in a diversified and supervised portfolio of common stocks, or securities convertible into common stocks, believed by management to have growth potential over the years. In pursuing the fund’s investment objective, the fund management team seeks to minimize the recognition of capital gains.

It is possible that in extreme market conditions the fund temporarily may invest some or all of its assets in high quality money market securities. Such a temporary defensive strategy would be inconsistent with the fund’s primary investment strategies. The reason for acquiring money market securities would be to avoid market losses. However, if market conditions improve, this strategy could result in reducing the potential gain from the market upswing, thus reducing the fund’s opportunity to achieve its investment goal.

As part of its normal operations, the fund may hold high quality money market securities pending investments or when it expects to need cash to pay redeeming shareholders. The fund will not deviate from its normal strategies if it holds these securities pending investments.

The fund generally follows a buy and hold approach in which turnover and corresponding capital gains are minimized. The fund generally will sell a stock when, in the management team’s opinion, there is a fundamental change in the company’s underlying business or a significant deterioration in growth prospects.

The management team may, when consistent with the fund’s investment goal, buy or sell options or futures on a security or an index of securities (collectively, commonly known as derivatives). An option is the right to buy or sell an instrument at a specific price on or before a specific date. A future is an agreement to buy or sell an instrument at a specific price on a specific date. The primary purpose of using derivatives is to attempt to reduce risk to the fund as a whole (hedge) but they may also be used to maintain liquidity and commit cash pending investment. The management team also may, but under normal market conditions generally does not intend to, use derivatives for speculation to increase returns.

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Should the Company’s Board of Trustees determine that the investment goal of the fund should be changed, shareholders will be given at least 30 days notice before any such change is made. However, such change can be effected without shareholder approval.

Key Risks

The main risk of any investment in stocks is that values fluctuate in price. The value of your investment can go up or down depending upon market conditions, which means you could lose money.

Because different kinds of stocks go in and out of favor depending on market conditions, this fund’s performance may be better or worse than other funds with different investment styles.

The fund may invest in securities prior to their date of issue. These securities could fall in value by the time they are actually issued, which may be any time from a few days to over a year.

The fund’s use of derivatives may reduce the fund’s returns and/or increase volatility. Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the fund’s use of derivatives is that the fluctuations in their values may not correlate perfectly with the overall securities markets. Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation. In addition, some derivatives are more sensitive to interest rate changes and market price fluctuations than other securities. The possible lack of a liquid secondary market for derivatives and the resulting inability of the fund to sell or otherwise close a derivatives position could expose the fund to losses. The fund could also suffer losses related to its derivatives positions as a result of unanticipated market movements, which losses are potentially unlimited. Finally, BlackRock may not be able to predict correctly the direction of securities prices, interest rates and other economic factors, which could cause the fund’s derivatives positions to lose value.

When you invest in this fund you are not making a bank deposit. Your investment is not insured or guaranteed by the Federal Deposit Insurance Corporation or by any bank or governmental agency.

Risk / Return Information

On January 31, 2005, the fund reorganized with the State Street Research Exchange Fund (the SSR Fund). The SSR Fund transferred substantially all of its assets and liabilities to the fund in exchange for shares of the fund, which were then distributed to SSR Fund shareholders. For periods prior to January 31, 2005, the chart and table below show performance information for the

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SSR Fund, which had substantially similar investment goals and strategies as the fund. The chart and table give you a picture of long-term performance for BlackRock Shares. The information shows you how performance has varied year by year and provides some indication of the risks of investing in the fund. The table compares the performance to that of the S&P 500^® Index, a recognized unmanaged index of stock market performance. As with all such investments, past performance (before and after taxes) is not an indication of future results. If certain SSR Fund expenses had not been waived or reimbursed during these periods, returns would have been lower.

As of 12/31

ANNUAL TOTAL RETURNS*

As of 12/31/04

AVERAGE ANNUAL TOTAL RETURNS*

	1 Year	3 Years	5 Years	10 Years	Inception Date1
Exchange
Return Before Taxes	7.63%	1.86%	-1.90%	11.89%	12/17/76
Return After Taxes on Distributions	7.08%	1.39%	-2.37%	11.22%
Return After Taxes on Distributions and Sale of Shares	4.45%	1.30%	-1.86%	10.26%
S&P 500® (Reflects no deduction for fees, expenses or taxes)	10.88%	3.59%	-2.30%	12.07%	N/A

* The chart and the table both assume reinvestment of dividends and distributions. Source: BlackRock Advisors, Inc.

¹ Inception date of the SSR Fund’s oldest class(es).

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold

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IMPORTANT DEFINITIONS

Advisory Fees: Fees paid to the investment adviser for portfolio management services.

Other Expenses: Include administration, transfer agency, custody, professional fees and registration fees.

their shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Expenses and Fees

As a shareholder you pay certain fees and expenses. Annual fund operating expenses are paid out of fund assets.

The table below describes the fees and expenses that you may pay if you buy and hold BlackRock Shares of the fund. The “Annual Fund Operating Expenses” table may not reflect expenses of the fund after February 1, 2007.

Annual Fund Operating Expenses

(Expenses that are deducted from fund assets)

Advisory fees	0.50	%
Other expenses	0.24	%
Total annual fund operating expenses	0.74	%
Fee waivers and expense reimbursements*	0.14	%
Net expenses*	0.60	%

  * BlackRock has contractually agreed to waive or reimburse fees or expenses in order to limit BlackRock Class expenses to 0.60% of average daily net assets until February 1, 2007. See the “Management” section for a discussion of these waivers and reimbursements.

Example:

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. We are assuming an initial investment of $10,000, 5% total return each year with no changes in operating expenses and redemption at the end of each time period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year		3 Years		5 Years		10 Years
BlackRock Shares	$	61	$	208	$	383	$	891

Fund Management

The fund management team is led by Jeffrey R. Lindsey, CFA, Managing Director at BlackRock Advisors, Inc. (BlackRock), and Edward P. Dowd, Director at BlackRock. Mr. Lindsey and Mr. Dowd also lead the portfolio management team of the BlackRock Legacy Fund.

Mr. Lindsey and Mr. Dowd joined BlackRock following the merger with State Street Research & Management (SSRM) in 2005. Prior to joining BlackRock, Mr. Lindsey, a co-portfolio manager of the SSR Legacy Fund since 2002, was a Managing Director and the Chief Investment Officer—Growth beginning in 2003, and was responsible for overseeing all of SSRM’s growth and core products. He was employed by SSRM beginning in 2002. During the past five years, he has also served as a Managing Director, Director of Concentrated Growth Products and Senior Vice President at Putnam Investments.

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Prior to joining BlackRock, Mr. Dowd was a Vice President at SSRM. He was employed by SSRM beginning in 2002 and was a co-portfolio manager of the SSR Legacy Fund. During the past five years, he also served as a Vice President and Technology Sector Leader for Independence Investment LLC and as an equity research associate at Donaldson, Lufkin & Jennrette.

Financial Highlights

The financial information in the table below shows financial performance for the periods indicated. For periods prior to January 31, 2005, the table shows performance information for the SSR Fund, which reorganized with the fund on that date. Certain information reflects results for a single fund share. The term “Total Return” indicates how much your investment would have increased or decreased during this period of time and assumes that you have reinvested all dividends and distributions. These figures have been audited by PricewaterhouseCoopers LLP (for periods ended on and before December 31, 2002) and Deloitte & Touche LLP (for periods ending after December 31, 2002). The independent registered public accountant’s report, along with the fund’s financial statements, are included in the Company’s annual report, which is available upon request (see back cover for ordering instructions). Deloitte & Touche LLP has been appointed as the Company’s independent registered public accountant for the current fiscal year.

FINANCIAL HIGHLIGHTS

(For a BlackRock Share Outstanding Throughout Each Period)

Exchange Portfolio

	Year Ended 12/31/04(b)			Year Ended 12/31/03			Year Ended 12/31/02(a)			Year Ended 12/31/01(a)			Year Ended 12/31/00(a)
Net asset value at beginning of period	$	490.99		$	411.01		$	511.71		$	575.76		$	616.80
Income from investment operations
Net investment income (loss)		7.61			5.40			4.74			4.22			4.75
Net gain (loss) on investments (both realized and unrealized)*		29.63			80.08			(100.64	)		(64.02	)		(41.19	)
Total from investment operations		37.24			85.48			(95.90	)		(59.80	)		(36.44	)
Less distributions
Distributions from net investment income		(7.50	)		(5.50	)		(4.80	)		(4.25	)		(4.60	)
Total distributions		(7.50	)		(5.50	)		(4.80	)		(4.25	)		(4.60	)
Net asset value at end of period	$	520.73		$	490.99		$	411.01		$	511.71		$	575.76
Total return		7.63	%		20.89	%		(18.78	)%		(10.35	)%		(4.13	)%
Ratios/Supplemental data
Net assets at end of period (in thousands)	$	299,352		$	309,699		$	268,503		$	367,640		$	437,804
Ratios of expenses to average net assets
Expense ratio		0.61	%		0.59	%		0.60	%		0.57	%		0.55	%
Expense ratio after expense reductions		0.61	%		0.59	%		0.60	%		0.57	%		0.55	%
Ratios of net investment income to average net assets		1.47	%		1.20	%		1.00	%		0.81	%		0.78	%
Portfolio turnover rate		3.96	%		5.47	%		3.32	%		1.44	%		10.51	%
*After provision for federal tax on retained capital gains at end of period		– –			– –			– –			– –			11.01

^(a) Audited by other auditors.

^(b) During the year ended December 31, 2004, the adviser reimbursed the fund as part of an internal review regarding the use of fund brokerage commissions. These payments increased net realized and unrealized gain investments per share by $0.17 and increased total return by 0.04%.

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About Your Investment

BlackRock, the Company’s distributor and their affiliates are permitted to make payments relating to distribution and sales support activities out of their past profits or other sources available to them (and not as an additional charge to the fund). BlackRock, the distributor and their affiliates may pay affiliated and unaffiliated brokers, dealers, financial institutions and industry professionals (Service Organizations) compensation for the sale and distribution of shares of the fund or for other services to the fund and shareholders. These payments (Additional Payments) would be in addition to the fund payments described in this Prospectus and may be a fixed dollar amount, may be based on the number of customer accounts maintained by the Service Organization, or may be based on a percentage of the value of shares sold to, or held by, customers of the Service Organization. The aggregate amount of Additional Payments may be substantial. The Additional Payments include amounts that are sometimes referred to as “revenue sharing” payments. In some circumstances, these revenue sharing payments may create an incentive for a Service Organization, its employees or associated persons to recommend or sell shares of a fund to you. Please contact your Service Organization for details about Additional Payments it may receive. For more information on Additional Payments, see the SAI.

Price Per Share

The price of mutual fund shares generally changes every day the New York Stock Exchange is open (business day). A mutual fund is a pool of investors’ money that is used to purchase a portfolio of securities, which in turn is owned in common by the investors. Investors put money into a mutual fund by buying shares. If a mutual fund has a portfolio worth $50 million and has 5 million shares outstanding, the net asset value (NAV) per share is $10.

NAV is calculated separately for each class of shares of the fund as of the close of business on the NYSE, generally 4 p.m. (Eastern time), each day the NYSE is open. Shares will not be priced on days the NYSE is closed. Non-U.S. securities and certain other securities held by the fund may trade on days when the NYSE is closed. In these cases, net asset value of shares may change when fund shares cannot be bought or sold.

Each of the Company’s fund’s assets are valued primarily on the basis of market quotations. Certain short-term debt securities are valued on the basis of amortized cost. When a determination is

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made that market quotations are not readily available, including, but not limited to, when (i) the exchange or market on which a security is traded does not open for trading for an entire trading day and no other market prices are available, (ii) a particular security does not trade regularly or has had its trading halted, (iii) a security does not have a price source due to its lack of liquidity, (iv) BlackRock believes a market quotation from a broker-dealer is unreliable (e.g., where it varies significantly from a recent trade), (v) the security is thinly traded or (vi) there has been a significant subsequent event, each fund values the affected securities at fair value as determined by BlackRock pursuant to procedures adopted by the Company’s Board of Trustees. For example, in valuing a security that trades principally on a foreign market, a fund uses the most recent closing market price from the market on which the security principally trades, unless because of a significant event subsequent to the market close such closing market price, in BlackRock’s judgment, does not represent the current market value of the security. Because significant events could affect the value of a foreign security between the close of the foreign market where the security is principally traded and the time the fund calculates its NAV, such closing price may not be reflective of current market conditions. Therefore, a fund may adjust the closing market price of a foreign security as a result of a significant subsequent event to reflect what it believes to be the fair value of the security as of the time the fund calculates its NAV.

Fair value represents a good faith approximation of the value of a security. A security’s valuation may differ depending on the method used for determining value. Valuing securities at fair value involves greater reliance on judgment than valuation of securities based on readily available market quotations. The fair value of one or more securities may not, in retrospect, be the prices at which those assets could have been sold during the period in which the particular fair values were used in determining a fund’s NAV. As a result, a fund’s sale or redemption of its shares at NAV, at a time when a holding or holdings are valued at fair value, may have the effect of diluting or increasing the economic interest of existing shareholders.

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Selling Shares

Shareholders may place redemption orders by sending a written redemption request with a signature guarantee by an eligible guarantor institution to BlackRock Funds at the following addresses: by regular mail c/o PFPC Inc., P.O. Box 9819, Providence, RI 02940-8019 or by Overnight delivery c/o PFPC Inc., 101 Sabin Street, Pawtucket, RI 02860. Shares are redeemed at the NAV per share next determined after receipt of the redemption order minus any applicable redemption/exchange fee. See “Market Timing and Redemption/Exchange Fees” below. Payment for redeemed shares for which a redemption order is received before 4 p.m. (Eastern time) on a business day is normally made in Federal funds wired to the redeeming shareholder on the next business day, provided that the fund’s custodian is also open for business. Payment for redemption orders received after 4 p.m. (Eastern time) or on a day when the fund’s custodian is closed is normally wired in Federal funds on the next business day following redemption on which the fund’s custodian is open for business. The Company reserves the right to wire redemption proceeds within seven days after receiving a redemption order if, in the judgement of the Company, an earlier payment could adversely affect the fund. No charge for wiring redemption payments is imposed by the Company.

Market Timing and Redemption/Exchange Fees

The Board of Trustees of the Company has determined that the interests of long-term shareholders and the Company’s ability to manage its investments may be adversely affected when shares are repeatedly bought, sold or exchanged in response to short-term market fluctuations—also known as “market timing.” The Company’s funds are not designed for market timing organizations or other entities using programmed or frequent purchases and sales or exchanges. The exchange privilege for Investor Shares is not intended as a vehicle for short-term trading. Excessive purchase and sale or exchange activity may interfere with portfolio management, increase expenses and taxes and may have an adverse effect on the performance of a fund and its shareholders. For example, large flows of cash into and out of a fund may require the management team to allocate a significant amount of assets to cash or other short-term investments or sell securities, rather than maintaining such assets in securities selected to achieve the fund’s investment goal. Frequent trading may cause a fund to sell securities at less favorable prices, and transaction costs, such as brokerage commissions, can reduce a fund’s performance.

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A fund that invests in non-U.S. securities is subject to the risk that an investor may seek to take advantage of a delay between the change in value of the fund’s portfolio securities and the determination of the fund’s NAV as a result of different closing times of U.S. and non-U.S. markets by buying or selling fund shares at a price that does not reflect their true value. A similar risk exists for funds that invest in securities of small capitalization companies, securities of issuers located in emerging markets or high yield securities (junk bonds) that are thinly traded and therefore may have actual values that differ from their market prices. This short-term arbitrage activity can reduce the return received by long-term shareholders. The Company will seek to eliminate these opportunities by using fair value pricing, as described in “Price Per Share” above.

The Company discourages market timing and seeks to prevent frequent purchases and sales or exchanges of fund shares that it determines may be detrimental to a fund or long-term shareholders. The Board of Trustees has approved the policies discussed below to seek to deter market timing activity. The Board has not adopted any specific numerical restrictions on purchases, sales and exchanges of fund shares because legitimate strategies, such as asset allocation, dollar cost averaging or similar activities, may result in frequent trading of fund shares. It is not expected that shareholders would be harmed by such legitimate activities.

If the Company believes, in its sole discretion, that your short-term trading is excessive or that you are engaging in market timing activity, it reserves the right to reject any specific purchase or exchange order. If the Company rejects your purchase or exchange order, you will not be able to execute that transaction, and the Company will not be responsible for any losses you therefore may suffer. In addition, any redemptions or exchanges that you make (as a result of the activity described above or otherwise) will be subject to any and all redemption/exchange fees, as described below. For transactions placed directly with the Company, the Company may consider the trading history of accounts under common ownership or control for the purpose of enforcing these policies. Transactions placed through the same financial intermediary on an omnibus basis may be deemed part of a group for the purpose of this policy and may be rejected in whole or in part by the Company. Certain accounts, such as omnibus accounts and accounts at financial intermediaries, however, include multiple investors and such accounts typically

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provide the Company with net purchase or redemption and exchange requests on any given day where purchases, redemptions and exchanges of shares are netted against one another and the identity of individual purchasers, redeemers and exchangers whose orders are aggregated are not known by the Company. While the Company monitors for market timing activity, the Company may be unable to identify such activities because the netting effect in omnibus accounts often makes it more difficult to locate and eliminate market timers from the funds. Identification of market timers may also be limited by operational systems and technical limitations. In the event that a financial intermediary is determined by the Company to be engaged in market timing or other improper trading activity, the Company’s distributor may terminate such financial intermediary’s agreement with the distributor, suspend such financial intermediary’s trading privileges or take other appropriate actions.

Each of the equity funds will automatically assess and retain a fee of 2% of the current NAV, after excluding the effect of any contingent deferred sales charges, of shares being redeemed or exchanged within 90 days of acquisition (other than those acquired through reinvestment of dividends or other distributions). Each of the High Yield Bond and International Bond Portfolios will automatically assess and retain a fee of 2% of the current NAV, after excluding the effect of any contingent deferred sales charges, of shares being redeemed or exchanged within 30 days of acquisition (other than those acquired through reinvestment of dividends or other distributions). A new 90-day period, or 30-day period, as the case may be, begins with each acquisition of shares through a purchase or exchange. For example, a series of transactions in which shares of Portfolio A are exchanged for shares of Portfolio B 20 days after the purchase of the Portfolio A shares, followed in 20 days by an exchange of the Portfolio B shares for shares of Portfolio C, will be subject to two redemption fees (one on each exchange).

The redemption/exchange fee is for the benefit of the remaining shareholders of a fund and is intended to encourage long-term investment, to compensate for transaction and other expenses caused by early redemptions and exchanges, and to facilitate portfolio management. The “first-in, first-out” method is used to determine the holding period. Under this method, the date of redemption or exchange will be compared with the earliest purchase date of shares held in the account. The Company sells

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shares to some 401(k) plans, 403(b) plans, bank or trust company accounts, and accounts of certain financial institutions or intermediaries that do not apply the redemption/exchange fee to underlying shareholders, often because of administrative or systems limitations. From time to time, with the approval of the Company, the redemption/exchange fee will not be assessed on redemptions or exchanges by: (i) accounts of asset allocation programs or wrap programs whose trading practices are determined by the Company not to be detrimental to a fund or long-term shareholders (e.g., model driven programs with periodic automatic portfolio rebalancing that prohibit participant-directed trading and other programs with similar characteristics); (ii) accounts of shareholders who have died or become disabled; (iii) shareholders redeeming or exchanging shares through the Company’s Systematic Withdrawal Plan, Systematic Exchange Plan or in connection with required distributions from an IRA, 401(k) plan, 403(b) plan or any other Internal Revenue Code Section 401 qualified retirement plan or account; and (iv) certain other accounts in the absolute discretion of the Company when a shareholder can demonstrate hardship. In addition, former State Street Research fund shareholders will not be charged a redemption/exchange fee in connection with a one-time redemption or exchange of Company shares received in a reorganization of a State Street Research fund with one of the Company’s funds. However, additional Company shares purchased by such shareholders after the reorganization and any Company shares acquired through an exchange after the reorganization will be subject to the fee. The Company reserves the right to modify or eliminate these waivers at any time.

The Company's Rights

The Company may:

n Suspend the right of redemption if trading is halted or restricted on the NYSE or under other emergency conditions described in the Investment Company Act,

n Postpone date of payment upon redemption if trading is halted or restricted on the NYSE or under other emergency conditions described in the Investment Company Act or as described in the section “Selling Shares” above, and

n Redeem shares for property other than cash if conditions exist which make cash payments undesirable in accordance with its rights under the Investment Company Act.

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IMPORTANT DEFINITIONS

Adviser: The adviser of a mutual fund is responsible for the overall investment management of the fund. The adviser for BlackRock Funds is BlackRock Advisors, Inc.

Statements

Every shareholder automatically receives regular account statements. In addition, for tax purposes, shareholders also receive a yearly statement describing the characteristics of any dividends or other distributions received.

Management

BlackRock Funds’ adviser is BlackRock Advisors, Inc. (BlackRock). BlackRock was organized in 1994 to perform advisory services for investment companies and is located at 100 Bellevue Parkway, Wilmington, DE 19809. BlackRock is a wholly-owned subsidiary of BlackRock, Inc., one of the largest publicly traded investment management firms in the United States with $341.8 billion of assets under management as of December 31, 2004. BlackRock, Inc. is a majority-owned indirect subsidiary of The PNC Financial Services Group, Inc., one of the largest diversified financial services companies in the United States.

For its investment advisory services, BlackRock is entitled to fees computed daily and payable monthly.

The total annual advisory fees that can be paid to BlackRock (as a percentage of average daily net assets of the fund) are .50% of average daily net assets.

The aggregate advisory fee paid by the Exchange Fund to State Street Research & Management Company, as a percentage of average daily net assets, for the fund’s most recent fiscal year was 0.50%.

As discussed above, BlackRock has agreed contractually to cap net expenses (excluding interest expense, taxes, brokerage commissions and extraordinary expenses, if any) of BlackRock Shares of the fund at the levels shown in the fund’s expense table.

To achieve this cap, BlackRock and the Company have entered into an expense limitation agreement. The agreement sets a limit on certain of the operating expenses of BlackRock Shares of the fund and requires BlackRock to waive or reimburse fees or expenses if these operating expenses exceed that limit.

Dividends and Distributions

BlackRock Funds makes two kinds of distributions to shareholders: net investment income and net realized capital gains.

Distributions of net investment income derived by the fund are paid within 10 days after the end of each quarter. The Company’s Board of Trustees may change the timing of such dividend payments.

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The fund’s current practice is to retain long-term capital gains and to pay federal taxes thereon at corporate capital gains tax rates on behalf of shareholders.

Your distributions will be reinvested at net asset value in new shares of the same class of the fund unless you instruct PFPC Inc. in writing to pay them in cash. There are no sales charges on these reinvestments.

If you invest in a fund shortly before it makes a capital gain distribution, some of your investment may be returned to you in the form of a taxable distribution. This is commonly known as “buying a dividend.” Distributions that are declared in December, but paid in January are taxable as if they were paid in December.

Taxation of Distributions

Distributions paid out of the fund’s “net capital gain” will be taxed to shareholders as long-term capital gain, regardless of how long a shareholder has owned shares. However, the fund intends to retain its net capital gain and pay the tax thereon for the benefit of the shareholders. As a result, each shareholder will (i) be required to include in income for U.S. federal income tax purposes as long-term capital gain its share of such undistributed amounts, (ii) be entitled to credit its proportionate share of the tax paid by the fund against its U.S. federal income tax liability and to claim refunds to the extent that the credit exceeds such liability and (iii) increase its basis in its shares of the fund by an amount equal to the difference between its proportionate share of such gains and the amount of the tax paid on such shareholder’s behalf by the fund.

Distributions of net investment income, other than exempt interest dividends, and net short-term capital gains will generally be taxed to shareholders as ordinary income. However, individual shareholders who satisfy certain holding period requirements and other requirements are taxed on such dividends at long-term capital gain rates to the extent the dividends are attributable to “qualified dividend income” received by the fund. “Qualified dividend income” generally consists of dividends received from U.S. corporations (other than dividends from tax exempt organizations and certain dividends from real estate investment trusts and regulated investment companies) and certain foreign corporations.

Your annual tax statement from the Company will present in detail the tax status of your distributions for each year.

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If more than half of the total asset value of the fund is invested in non-U.S. stock or securities, the fund may elect to “pass through” to its shareholders the amount of non-U.S. income taxes paid by it. In such case, you would be required to include your proportionate share of such taxes in your income and may be entitled to deduct or credit such taxes when computing your taxable income.

Distributions paid by the fund with respect to certain qualifying dividends received by the fund from domestic corporations may be eligible for the corporate dividends received deduction.

If you do not provide a fund with your proper taxpayer identification number and certain required certifications, you may be subject to backup withholding on any distributions of income, capital gains or proceeds from the sale of your shares. When withholding is required, the amount will be 28% of any distributions or proceeds paid. Backup withholding is not an additional tax. Any amounts withheld may be credited against your U.S. federal income tax liability.

Non-U.S. investors may be subject to U.S. withholding and/or estate tax, and will be subject to special U.S. tax certification requirements. Because every investor has an individual tax situation, and also because the tax laws are subject to periodic changes, you should always consult your tax professional about federal, state and local tax consequences of owning shares of the Company.

Important Notice Regarding Delivery of Shareholder Documents

The fund delivers only one copy of shareholder documents, including prospectuses, shareholder reports and proxy statements to shareholders with multiple accounts at the same address. This practice is known as “householding” and is intended to eliminate duplicate mailings and reduce expenses. Mailings of your shareholder documents may be householded indefinitely unless you instruct us otherwise. If you do not want the mailing of these documents to be combined with those for other members of your household, please contact BlackRock Funds at (800) 441-7762.

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Electronic Access to Annual Reports, Semi-Annual Reports and Prospectuses

Electronic copies of most financial reports and prospectuses are now available on the Company’s website. Shareholders can sign up for e-mail notifications of quarterly statements, annual and semi-annual reports and prospectuses by visiting BlackRock’s website if they enroll in the Company’s electronic delivery program.

To enroll:

Shareholders Who Hold Accounts with Investment Advisers, Banks or Brokerages:

Please contact your financial adviser. Please note that not all investment advisers, banks or brokerages may offer this service.

Shareholders Who Hold Accounts Directly With BlackRock

1)  Log on to http://www.blackrock.com/funds

2)  Click on the link for Electronic Delivery

3)  Continue to Account Access

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For more information:

This Prospectus contains important information you should know before you invest. Read it carefully and keep it for future reference. More information about the BlackRock Funds is available at no charge upon request. This information includes:

Annual/Semi-Annual Reports

These reports contain additional information about the fund’s investments. The annual report describes the fund’s performance, lists portfolio holdings, and discusses recent market conditions, economic trends and fund investment strategies that significantly affected the fund’s performance for the last fiscal year.

Statement of Additional Information (SAI)

A Statement of Additional Information, dated January 31, 2005, has been filed with the Securities and Exchange Commission (SEC). The SAI, which includes additional information about the BlackRock Funds, may be obtained free of charge, along with the Company’s annual and semi-annual reports, by calling (800) 441-7762. The SAI, as supplemented from time to time, is incorporated by reference into this Prospectus.

Shareholder Account Service Representatives

Representatives are available to discuss account balance information, mutual fund prospectuses, literature, programs and services available. Hours: 8:00 a.m. to 6:00 p.m. (Eastern time), Monday-Friday. Call: (800) 441-7762.

World Wide Web

Access general fund information and specific fund performance. Request mutual fund prospectuses and literature. Forward mutual fund inquiries. www.blackrock.com/funds

Written Correspondence

BlackRock Funds

c/o PFPC Inc.

P.O. Box 9819

Providence, RI 02940-8019

For Overnight Delivery

BlackRock Funds

c/o PFPC Inc.

101 Sabin Street

Pawtucket, RI 02860

Portfolio Characteristics and Holdings

A description of the BlackRock Funds’ policies and procedures related to disclosure of portfolio characteristics and holdings is available in the SAI.

For information about portfolio holdings and characteristics, BlackRock fund shareholders and prospective investors may call (800) 882-0052.

Securities and Exchange Commission (SEC)

You may also view and copy public information about the BlackRock Funds, including the SAI, by visiting the EDGAR database on the SEC Web site (http://www.sec.gov) or the SEC’s Public Reference Room in Washington, D.C. Information about the operation of the public reference room can be obtained by calling the SEC directly at (202) 942-8090. Copies of this information can be obtained, for a duplicating fee, by electronic request at the following E-mail address: publicinfo@sec.gov, or by writing to the Public Reference Section of the SEC, Washington, D.C. 20549-0102.

INVESTMENT COMPANY ACT FILE NO. 811-05742

PRO-EX-BLK 02/05