<?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>0001059235</rptOwnerCik>
            <rptOwnerName>WAGNER SUSAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O 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>Chief Operating Officer</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>9722</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21087</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 as to approximately 53% of the Restricted Stock Units on the first anniversary of January 31, 2006 and as to approximately 23.5% of the Restricted Stock Units on each of the second and third anniversaries of January 31, 2006.</footnote>
        <footnote id="F2">Includes 2,403 shares of Class A Common Stock acquired under the BlackRock, Inc. Employee Stock Purchase Plan through July 31, 2005.  Also includes 1,201 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 Susan Wagner</signatureName>
        <signatureDate>2006-01-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
