<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-03-19</periodOfReport>

    <issuer>
        <issuerCik>0001390332</issuerCik>
        <issuerName>STONE TAN CHINA ACQUISITION CORP.</issuerName>
        <issuerTradingSymbol>STTA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001319244</rptOwnerCik>
            <rptOwnerName>INTEGRATED CORE STRATEGIES (US) LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MILLENNIUM MANAGEMENT LLC</rptOwnerStreet1>
            <rptOwnerStreet2>666 FIFTH AVENUE, 8TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10103-0899</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>May be deemed a group member.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001446811</rptOwnerCik>
            <rptOwnerName>COGNIZANT HOLDINGS, LTD.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MILLENNIUM MANAGEMENT LLC</rptOwnerStreet1>
            <rptOwnerStreet2>666 FIFTH AVENUE, 8TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10103-0899</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>May be deemed a group member.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001426821</rptOwnerCik>
            <rptOwnerName>MILLENNIUM INTERNATIONAL MANAGEMENT LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>666 FIFTH AVENUE, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK, NY 10103</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10103-0899</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>May be deemed a group member.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001446830</rptOwnerCik>
            <rptOwnerName>MILLENNIUM INTERNATIONAL MANAGEMENT GP LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>666 FIFTH AVENUE, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10103-0899</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>May be deemed a group member.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001273087</rptOwnerCik>
            <rptOwnerName>MILLENNIUM MANAGEMENT LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>666 FIFTH AVENUE, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10103-0899</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>May be deemed a group member.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001017456</rptOwnerCik>
            <rptOwnerName>ENGLANDER ISRAEL A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MILLENNIUM MANAGEMENT LLC</rptOwnerStreet1>
            <rptOwnerStreet2>666 FIFTH AVENUE, 8TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10103-0899</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>May be deemed a group member.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-03-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>210510</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-03-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>210510</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4198460</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Form 4 is being filed to report the transfer of 210,510 shares of common stock, par value $0.0001 per share (&quot;Common Stock&quot;) of Stone Tan Acquisition Corp., a Delaware limited liability company (the &quot;Issuer&quot;) held by Cognizant Holdings, Ltd., an exempted limited company organized under the laws of the Cayman Islands (&quot;Cognizant Holdings&quot;) to Integrated Core Strategies (US) LLC, a Delaware limited liability company (&quot;Integrated Core Strategies&quot;), each of which is wholly-owned by the same entity, as a result of which Integrated Core Strategies may be deemed to beneficially own those shares of the Issuer's Common Stock.  For all filers except Cognizant Holdings, such transaction was exempt under Rule 16a-13 promulgated under the Securities Exchange Act of 1934.  As a result of this transfer, Cognizant Holdings is no longer a beneficial owner of any shares of the Issuer's Common Stock.</footnote>
        <footnote id="F2">As of the date of this filing, Integrated Core Strategies is the beneficial owner of 4,198,150 shares of the Issuer's Common Stock.</footnote>
        <footnote id="F3">As of the date of this filing, Integrated Core Strategies also holds 2,887,420 warrants to purchase the Issuer's Common Stock (&quot;Warrants&quot;). Each Warrant will entitle the holder to purchase one share of the Issuer's Common Stock at a price of $5.50.  Each Warrant will become exercisable upon the Issuer's completion of a business combination.  However, no Warrants will be exercisable unless at the time of exercise a prospectus relating to the Common Stock issuable upon exercise of the Warrants is current and the shares of Common Stock have been registered or qualified or deemed to be exempt under the securities laws of the state of residence of the holder of the Warrants.  The Warrants will expire on October 15, 2011, or earlier upon redemption.  As of the date of this filing, the Issuer has not announced the completion of a business combination and therefore, the Warrants are not currently exercisable.</footnote>
        <footnote id="F4">Millennium International Management LP, a Delaware limited partnership (&quot;Millennium International Management&quot;), is the investment manager to Cognizant Holdings, and may be deemed to have shared voting control and investment discretion over securities owned by Cognizant Holdings. Millennium International Management GP LLC, a Delaware limited liability company (&quot;Millennium International Management GP&quot;), is the general partner of Millennium International Management, and thus may be deemed to have shared voting control and investment discretion over securities owned by Cognizant Holdings. The foregoing should not be construed in and of itself as an admission by Millennium International Management or Millennium International Management GP as to beneficial ownership of the securities owned by Cognizant Holdings.</footnote>
        <footnote id="F5">Millennium Management LLC, a Delaware limited liability company (&quot;Millennium Management&quot;), is the general partner of the managing member of Integrated Core Strategies, and may be deemed to have shared voting control and investment discretion over securities owned by Integrated Core Strategies. Millennium Management is also is the general partner of the 100% shareholder of Cognizant Holdings, and may be deemed to have shared voting control and investment discretion over securities owned by Cognizant Holdings.</footnote>
        <footnote id="F6">Israel A. Englander (&quot;Mr. Englander&quot;) is the managing member of Millennium Management and of Millennium International Management GP. Consequently, Mr. Englander may be deemed to be the beneficial owner of any securities owned by Integrated Core Strategies and/or Cognizant Holdings, as the case may be. The foregoing should not be construed in and of itself as an admission by Millennium Management or Mr. Englander as to beneficial ownership of the securities owned by Integrated Core Strategies and/or Cognizant Holdings, as the case may be.</footnote>
    </footnotes>

    <remarks>*INTEGRATED CORE STRATEGIES (US) LLC, By: Integrated Holding Group LP, its managing member, By: Millennium Management LLC, its general partner, By: David Nolan, Co-President</remarks>

    <ownerSignature>
        <signatureName>*David Nolan, Co-President</signatureName>
        <signatureDate>2009-03-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
