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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-01-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001060021</issuerCik>
        <issuerName>BLACKROCK INC /NY</issuerName>
        <issuerTradingSymbol>BLK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001210400</rptOwnerCik>
            <rptOwnerName>CONNOLLY ROBERT</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BLACKROCK, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>40 EAST 52ND STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>General Counsel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Shares of Class A Common Stock (par value $0.01 per share)</value>
            </securityTitle>
            <transactionDate>
                <value>2006-01-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3093</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24676</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Restricted Stock Units granted under the 1999 Stock Award and Incentive Plan, based on $113.13 per share which was 90% of the average of the high and low price per share of the Class A Common Stock on January 23, 2006, the formula having been approved by the Compensation Committee of the Board of Directors on January 11, 2006.  Each Restricted Stock Unit is payable solely by delivery of an equal number of shares of Class A Common Stock and vests one-third on each of the first, second and third anniversaries of January 31, 2006.</footnote>
        <footnote id="F2">Includes 2,319 shares of Class A Common Stock acquired under the BlackRock, Inc. Employee Stock Purchase Plan through July 31, 2005.  Also includes 1,130 shares of Class A Common Stock acquired by the reporting person through December 31, 2005 under The PNC Financial Services Group, Inc. Incentive Savings Plan (the &quot;ISP&quot;).  The information on this report with respect to the ISP is based on a plan statement dated as of December 31, 2005.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Daniel R. Waltcher as Attorney-in-Fact for Robert P. Connolly</signatureName>
        <signatureDate>2006-01-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
