Form 485APOS for iShares Trust

The information in this Prospectus is not complete and may be changed. A registration statement relating to these securities has been filed with the Securities and Exchange Commission. The securities described herein may not be sold until the registration statement becomes effective. This Prospectus is not an offer to sell or the solicitation of an offer to buy securities and is not soliciting an offer to buy these securities in any state in which the offer, solicitation or sale would be unlawful.

Distribution	25
Financial Highlights	27
Index Providers	27
Disclaimer	27
Supplemental Information	33

“Standard & Poor’s^®,” “S&P^®,” “S&P Target Date Retirement Income Index,” “S&P Target Date 2010 Index,” “S&P Target Date 2015 Index,” “S&P Target Date 2020 Index,” “S&P Target Date 2025 Index,” “S&P Target Date 2030 Index,” “S&P Target Date 2035 Index,” “S&P Target Date 2040 Index,” “S&P Target Date 2045 Index” and “S&P Target Date 2050 Index” are trademarks of Standard & Poor’s Financial Services LLC (a subsidiary of The McGraw-Hill Companies) licensed for use for certain purposes by BlackRock Institutional Trust Company, N.A. (“BTC”). iShares^® is a registered trademark of BTC.

The iShares S&P Target Date Retirement Income Index Fund (the “Fund”) seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the S&P Target Date Retirement Income Index (the “Underlying Index”).

You will also incur usual and customary brokerage commissions when buying or selling shares of the Fund, which are not reflected in the example that follows:

Portfolio Turnover. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 14% of the average value of its portfolio.

The Fund is a fund of funds and seeks its investment objective by investing primarily in the securities of other iShares funds (each, an “Underlying Fund” and collectively, the “Underlying Funds”) that themselves seek investment results corresponding to their own underlying index. The Underlying Funds invest primarily in distinct asset classes, such as large-capitalization U.S. equity, mid-capitalization U.S. equity, emerging market securities, the aggregate bond market or the U.S. treasury bond market; each such asset class has its own risk profile.

It is the goal of the Underlying Index to represent an allocation strategy geared towards investors who are currently retired or are close to retirement.

The Underlying Index seeks to represent asset allocations which reflect an immediate retirement horizon, i.e., asset allocations geared toward investors who are currently retired or are close to retirement, but only you can determine whether or not the Fund’s asset allocation reflects your risk tolerance and investment needs. The Fund may not be appropriate for all investors who are currently retired or are close to retirement. The Underlying Index’s asset allocation is not static and may change over time. While the Underlying Index has an asset allocation that is intended to be appropriate for a person who is currently retired, the Fund is still exposed to risk of loss and could suffer significant losses. There is no guarantee that the Fund will provide adequate income through your retirement.

The Fund is designed to broadly meet the investment objectives of investors nearing or currently in retirement by tracking the Underlying Index. As of ___________, the Fund invested approximately 35% of its assets in Underlying Funds that invest primarily in equity securities and 64% of its assets in Underlying Funds that invest primarily in bonds.

BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.

Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by keeping portfolio turnover low in comparison to actively managed investment companies.

BFA uses a representative sampling indexing strategy to manage the Funds. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market capitalization and industry weightings), fundamental characteristics (such as return variability and yield) and liquidity measures similar to those of the Underlying Index. The Fund may or may not hold all of the securities in the Underlying Index. Funds that employ a representative sampling strategy may incur tracking error risk to a greater extent than a fund that seeks to replicate an index.

The Fund generally invests at least 90% of its assets in securities of the Underlying Index. The Fund may invest the remainder of its assets in securities not included in the Underlying Index, but which BFA believes will help the Fund track its Underlying Index, futures contracts, options on futures contracts and options, as well as cash and cash equivalents, including shares of money market funds affiliated with BFA or its affiliates, to the extent permitted under the Investment Company Act of 1940, as amended (the “1940 Act”).

The Underlying Index is sponsored by an organization (the “Index Provider”) that is independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index. The Fund’s Index Provider is Standard & Poor’s Financial Services LLC (a subsidiary of The McGraw-Hill Companies) (“S&P”).

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to the principal risks noted below (either directly or through its investments in the Underlying Funds), any of which may adversely affect the Fund’s NAV, trading price, yield, total return and ability to meet its investment objective.

Asset Class Risk. Securities in the Underlying Index or in the Fund’s portfolio may underperform in comparison to the general securities markets or other asset classes.

Credit Risk. The risk that debt issuers and other counterparties may not honor their obligations.

Emerging Markets Risk. Investments in emerging markets may be subject to a greater risk of loss than investments in more developed markets.

Equity Securities Risk. Equity securities are subject to changes in value and their values may be more volatile than other asset classes.

Interest Rate Risk. An increase in interest rates may cause the value of fixed-income securities held by the Fund or an Underlying Fund to decline.

Issuer Risk. Fund performance depends on the performance of individual securities to which the Fund or an Underlying Fund will have exposure. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline. There is no guarantee that an issuer that paid dividends in the past will continue to do so in the future or will continue paying dividends at the same level.

Management Risk. As the Fund does not fully replicate the Underlying Index, it is subject to the risk that BFA’s investment management strategy may not produce the intended results.

Market Risk. The Fund could lose money over short periods due to short-term market movements and over longer periods during market downturns.

Market Trading Risks. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, and disruption in the creation/redemption process of the Fund. ANY OF THESE FACTORS MAY LEAD TO THE FUND’S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

Mid-Capitalization Companies Risk. The Fund or an Underlying Fund invests in securities of mid-capitalization companies. Compared to large-capitalization companies, mid-capitalization companies may be less stable and their securities may be more volatile and less liquid.

Model Risk. Neither the Fund nor BFA can offer assurances that the Underlying Index’s allocation model will maximize returns or minimize risk, or be appropriate for every investor seeking a particular risk profile.

Non-U.S. Securities Risks. Investments in the securities of non-U.S. issuers are subject to the risks associated with investing in those non-U.S. markets, such as heightened risks of inflation or nationalization. The Fund may lose money due to political, economic and geographic events affecting a non-U.S. issuer or market.

Passive Investment Risk. The Fund is not actively managed and BFA does not attempt to take defensive positions in declining markets.

Reinvestment Risk. The Fund or an Underlying Fund invests in short-term fixed-income instruments, and may be adversely affected if interest rates fall because it may invest in lower yielding bonds as bonds in the portfolio mature.

Real Estate Company Risk. The Fund or an Underlying Fund invests in companies that invest in real estate and is exposed to risks specific to the real estate market, including interest rate risk, leverage risk, property risk and management risk.

Securities Lending Risk. The Fund or an Underlying Fund may engage in securities lending. Securities lending involves the risk that the Fund or an Underlying Fund may lose money because the borrower fails to return the securities in a timely manner, or at all. The Fund could also lose money in the event of a decline in the value of the collateral provided for loaned securities or of investments made with cash collateral. These events could also trigger adverse tax consequences for the Fund.

Small-Capitalization Companies Risk. The Fund or an Underlying Fund invests in securities of small-capitalization companies. Compared to mid- and large-capitalization companies, small-capitalization companies may be less stable and their securities may be more volatile and less liquid.

Tracking Error Risk. The performance of the Fund may diverge from that of the Underlying Index. Because the Fund employs a representative sampling strategy, the Fund may experience tracking error to a greater extent than a fund that seeks to replicate an index.

Valuation Risk. The value of the securities in the Fund’s portfolio may change on days when shareholders will not be able to purchase or sell the Fund’s shares.

The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund. Both assume that all dividends and distributions have been reinvested in the Fund. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Supplemental information about the Fund’s performance is shown under the heading Total Return Information in the Supplemental Information section of the Prospectus.

The best calendar quarter return during the period shown above was 7.73% in the 3rd quarter of 2009; the worst was -4.54% in the 1st quarter of 2009.

Updated performance information is available at www.iShares.com or by calling 1-800-iShares (1-800-474-2737) (toll free).

Portfolio Managers. Rene Casis, Diane Hsiung and Greg Savage (the “Portfolio Managers”) are primarily responsible for the day-to-day management of the Fund. Each Portfolio Manager supervises a portfolio management team. Mr. Casis, Ms. Hsiung and Mr. Savage have been Portfolio Managers of the Fund since 2010, inception and inception, respectively.

The Fund is an exchange-traded fund (commonly referred to as an “ETF”). Individual Fund shares may only be purchased and sold on a national securities exchange through a broker-dealer. The price of Fund shares is based on market price, and because ETF shares trade at market prices rather than NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). The Fund will only issue or redeem shares that have been aggregated into blocks of 50,000 shares or multiples thereof (“Creation Units”) to authorized participants who have entered into agreements with the Fund’s distributor. The Fund will issue or redeem Creation Units in return for a basket of assets that the Fund specifies each day.

The Fund intends to make distributions that may be taxable to you as ordinary income or capital gains, unless you are investing through a tax-deferred arrangement such as a 401(k) plan or an IRA.

If you purchase shares of the Fund through a broker-dealer or other financial intermediary (such as a bank), BFA or other related companies may pay the intermediary for marketing activities and presentations, educational training programs, conferences, the development of technology platforms and reporting systems or other services related to the sale or promotion of the Funds. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Funds over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

The iShares S&P Target Date 2010 Index Fund (the “Fund”) seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the S&P Target Date 2010 Index (the “Underlying Index”).

The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except interest expenses, taxes, brokerage expenses, future distribution fees or expenses, and extraordinary expenses. “Acquired Fund Fees and Expenses” reflect the Fund’s pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not used to calculate the Fund’s net asset value per share (“NAV”) and are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund’s prospectus (the “Prospectus”). BFA has contractually agreed to waive a portion of the advisory fee it is entitled to receive from the Fund due to its investments in other iShares funds, in an amount equal to 0.14%, through June 30, 2012. The contractual waiver may be terminated prior to June 30, 2012 only upon written agreement of the Trust and BFA.

You will also incur usual and customary brokerage commissions when buying or selling shares of the Fund, which are not reflected in the example that follows:

The retirement time horizon, also referred to as a “target date,” is included in the name of an Underlying Index and a Fund that invests in the securities of such Underlying Index. A Fund whose index name refers to a particular target date is designed for investors expecting to retire or to begin to gradually withdraw their money around such target date.

The Underlying Index seeks to represent asset allocations for investors with a target retirement horizon on or around 2010, but only you can determine whether or not the Fund’s asset allocation reflects your risk tolerance and investment needs. The Fund may not be appropriate for all investors with this target retirement horizon. The Underlying Index’s asset allocation may continue to grow more conservative after the target date. The Fund will continue to be exposed to risk of loss after the target date. There is no guarantee that the Fund will provide adequate income through your retirement.

The Fund is designed to broadly meet the investment objectives of investors with an approximate 2010 target retirement horizon by tracking the Underlying Index. As of ___________, the Fund invested approximately 48% of its assets in Underlying Funds that invest primarily in equity securities and 52% of its assets in Underlying Funds that invest primarily in bonds.