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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-03-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001362718</issuerCik>
        <issuerName>TIANYIN PHARMACEUTICAL CO., INC.</issuerName>
        <issuerTradingSymbol>TPI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001426116</rptOwnerCik>
            <rptOwnerName>CMARK HOLDINGS CO., LTD.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>UNIT 06, 21/F, BEAUTIFUL GROUP TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>77 CONNAUGHT ROAD</rptOwnerStreet2>
            <rptOwnerCity>CENTRAL</rptOwnerCity>
            <rptOwnerState>K3</rptOwnerState>
            <rptOwnerZipCode>000000</rptOwnerZipCode>
            <rptOwnerStateDescription>HONG KONG</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-03-23</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2010-03-23</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>161680</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.5</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>323035</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks>Cmark transferred these shares in a private transaction.</remarks>

    <ownerSignature>
        <signatureName>/s/ Stewart Lor as Director of Cmark Holdings, Inc. Ltd.</signatureName>
        <signatureDate>2010-04-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
