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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-12-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000320017</issuerCik>
        <issuerName>NeoStem, Inc.</issuerName>
        <issuerTradingSymbol>NBS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001554792</rptOwnerCik>
            <rptOwnerName>RimAsia Capital Partners Manager, Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1807 HARBOUR CENTRE</rptOwnerStreet1>
            <rptOwnerStreet2>25 HARBOUR ROAD WANCHAI</rptOwnerStreet2>
            <rptOwnerCity>HONG KONG</rptOwnerCity>
            <rptOwnerState>F4</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>CHINA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001369127</rptOwnerCik>
            <rptOwnerName>RimAsia Capital Partners, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1807 HARBOUR CENTRE</rptOwnerStreet1>
            <rptOwnerStreet2>25 HARBOUR ROAD, WANCHAI</rptOwnerStreet2>
            <rptOwnerCity>HONG KONG</rptOwnerCity>
            <rptOwnerState>F4</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>CHINA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001369125</rptOwnerCik>
            <rptOwnerName>RimAsia Capital Partners GP, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1807 HARBOUR CENTRE</rptOwnerStreet1>
            <rptOwnerStreet2>25 HARBOUR ROAD, WANCHAI</rptOwnerStreet2>
            <rptOwnerCity>HONG KONG</rptOwnerCity>
            <rptOwnerState>F4</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>CHINA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001369126</rptOwnerCik>
            <rptOwnerName>RimAsia Capital Partners GP, Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1807 HARBOUR CENTRE</rptOwnerStreet1>
            <rptOwnerStreet2>25 HARBOUR ROAD, WANCHAI</rptOwnerStreet2>
            <rptOwnerCity>HONG KONG</rptOwnerCity>
            <rptOwnerState>F4</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>CHINA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001368570</rptOwnerCik>
            <rptOwnerName>Wei Eric</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1807 HARBOUR CENTRE</rptOwnerStreet1>
            <rptOwnerStreet2>25 HARBOUR ROAD, WANCHAI</rptOwnerStreet2>
            <rptOwnerCity>HONG KONG</rptOwnerCity>
            <rptOwnerState>F4</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>CHINA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-08</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>16060</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2224928</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These securities are held as to 2,224,928 shares of Common Stock by RimAsia Capital Partners L.P., a Cayman Islands exempted limited partnership (&quot;RimAsia LP&quot;).</footnote>
        <footnote id="F2">This Form 4 is filed jointly by (a) RimAsia LP, (b) RimAsia Capital Partners GP, L.P. (&quot;RimAsia GP&quot;), the general partner of RimAsia LP, (c) RimAsia Capital Partners GP, Ltd. (&quot;RimAsia Ltd.&quot;), the general partner of RimAsia GP, (d) RimAsia Manager, the Fund Manager of RimAsia GP and the Manager of RimAsia LP, and (e) Eric H.C. Wei, the managing partner of RimAsia LP, an indirect partner of RimAsia GP, a director of RimAsia Ltd. and a director of RimAsia Manager.  All such reporting persons have the address noted in Item 1.</footnote>
        <footnote id="F3">RimAsia GP, RimAsia Ltd., RimAsia Manager and Eric H.C. Wei disclaim beneficial ownership of the securities held by RimAsia LP, and RimAsia LP, RimAsia GP, RimAsia Ltd. and Eric H.C. Wei disclaim beneficial ownership of the securities held by RimAsia LP in each case except to the extent of any pecuniary interest therein, and the inclusion of these securities shall not be deemed an admission of beneficial ownership of all of the reported securities for purposes of Section 16 of the Securities Exchange Act or for any other purpose.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>RIMASIA CAPITAL PARTNERS MANAGER, LTD., By: Eric H.C. Wei, Director, By: /s/ Catherine M. Vaczy, Esq., Attorney-in-Fact</signatureName>
        <signatureDate>2014-12-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>RIMASIA CAPITAL PARTNERS, L.P., By: Eric H.C. Wei, Managing Partner, By: /s/ Catherine M. Vaczy, Esq., Attorney-in-Fact</signatureName>
        <signatureDate>2014-12-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>RIMASIA CAPITAL PARTNERS GP, L.P., By: Eric H.C. Wei, Partner, By: /s/ Catherine M. Vaczy, Esq., Attorney-in-Fact</signatureName>
        <signatureDate>2014-12-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>RIMASIA CAPITAL PARTNERS GP, LTD., By: Eric H.C. Wei, Director, By: /s/ Catherine M. Vaczy, Esq., Attorney-in-Fact</signatureName>
        <signatureDate>2014-12-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>ERIC H.C. WEI, By: /s/ Catherine M. Vaczy, Esq., Attorney-in-Fact</signatureName>
        <signatureDate>2014-12-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
