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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-03-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000789868</issuerCik>
        <issuerName>AMERICAN DAIRY INC</issuerName>
        <issuerTradingSymbol>ADY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001444121</rptOwnerCik>
            <rptOwnerName>SEQUOIA CAPITAL US GROWTH FUND IV LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3000 SAND HILL ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>BLDG 4, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001470942</rptOwnerCik>
            <rptOwnerName>ZHOU KUI</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>SUITE 2215, 22/F, TWO PACIFIC PLACE</rptOwnerStreet1>
            <rptOwnerStreet2>88 QUEENSWAY ROAD</rptOwnerStreet2>
            <rptOwnerCity>N/A</rptOwnerCity>
            <rptOwnerState>K3</rptOwnerState>
            <rptOwnerZipCode>NA</rptOwnerZipCode>
            <rptOwnerStateDescription>HONG KONG</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001471126</rptOwnerCik>
            <rptOwnerName>SCGF GENPAR LTD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3000 SAND HILL ROAD 4-250</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001201045</rptOwnerCik>
            <rptOwnerName>MORITZ MICHAEL J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3000 SAND HILL ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>BUILDING 4, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001195580</rptOwnerCik>
            <rptOwnerName>LEONE DOUGLAS M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SEQUOIA CAPITAL</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD BLDG 4 #250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001222287</rptOwnerCik>
            <rptOwnerName>BOTHA ROELOF</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SEQUOIA CAPITAL</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD BLDG 4 #250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001312124</rptOwnerCik>
            <rptOwnerName>Carter J Scott</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SEQUOIA CAPITAL</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD, BLDG 4-250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001219231</rptOwnerCik>
            <rptOwnerName>GOETZ JAMES J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SEQUOIA CAPITAL</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD, BLDG 4, STE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001201421</rptOwnerCik>
            <rptOwnerName>GOGUEN MICHAEL L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SEQUOIA CAPITAL</rptOwnerStreet1>
            <rptOwnerStreet2>3000 SAND HILL RD BLDG 4 #250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001447940</rptOwnerCik>
            <rptOwnerName>SCGF IV MANAGEMENT LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3000 SAND HILL ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>BLDG 4, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-03-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>0</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>There are 2 filings of Form 4  Pls see Part I for information.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks>This report is one of two reports, each on a separate Form 4 on the date hereof, but relating to the same transactions being filed by the reporting persons. This version is Part II.</remarks>

    <ownerSignature>
        <signatureName>Sequoia Capital U.S. Growth Fund IV, L.P., By: SCGF IV Management, L.P., By: SCGF GenPar Ltd., By: /s/ Melinda Dunn as attorney-in-fact for Michael Mortiz, Douglas Leone, Roelof Botha, Scott Carter, James Goetz and Michael Goguen (Managing Directors)</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Kui Zhou</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Michael Moritz /s/ Melinda Dunn as Attorney-in-Fact</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Douglas Leone /s/ Melinda Dunn as Attorney-in-Fact</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SCGF IV Management, L.P., By: SCGF GenPar, Ltd., By: /s/ Melinda Dunn as Attorney-in-Fact for Michael Moritz, Douglas Leone, Roelof Botha, Scott Carter, James Goetz and Michael Goguen (Managing Directors)</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SCGF GenPar, Ltd. By: /s/ Melinda Dunn as Attorney-in-Fact for Michael Moritz, Douglas Leone, Roelof Botha, Scott Carter, James Goetz and Michael Goguen (Managing Directors)</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Scott Carter /s/ Melinda Dunn as Attorney-in-Fact</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>James Goetz /s/ Melinda Dunn as Attorney-in-Fact</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Michael Goguen /s/ Melinda Dunn as Attorney-in-Fact</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Roelof Botha /s/ Melinda Dunn as Attorney-in-Fact</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
