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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001209191-07-022947.txt : 20070406
<SEC-HEADER>0001209191-07-022947.hdr.sgml : 20070406
<ACCEPTANCE-DATETIME>20070406151503
ACCESSION NUMBER:		0001209191-07-022947
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070404
FILED AS OF DATE:		20070406
DATE AS OF CHANGE:		20070406

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LA JOLLA PHARMACEUTICAL CO
		CENTRAL INDEX KEY:			0000920465
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				330361285
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6455 NANCY RIDGE DR
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
		BUSINESS PHONE:		8584526600

	MAIL ADDRESS:	
		STREET 1:		6455 NANCY RIDGE DR
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Naini Nader J
		CENTRAL INDEX KEY:			0001344203

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-24274
		FILM NUMBER:		07754341

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(206) 621-7200

	MAIL ADDRESS:	
		STREET 1:		601 UNION STREET, SUITE 3200
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98101
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-04-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000920465</issuerCik>
        <issuerName>LA JOLLA PHARMACEUTICAL CO</issuerName>
        <issuerTradingSymbol>LJPC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001344203</rptOwnerCik>
            <rptOwnerName>Naini Nader J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>601 UNION STREET, SUITE 3200</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SEATTLE</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98101</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-04-04</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>833333</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4833333</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Frazier Healthcare V, LP</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These securities are held by Frazier Healthcare V, L.P. Mr. Naini is a managing member of FHM V, LLC (the general partner of FHM V, L.P., which is the general partner of Frazier Healthcare V, L.P.). As a managing member of FHM V, LLC, Mr. Naini shares voting and investment powers for securities held by Frazier Healthcare V. Mr. Naini and the Frazier entities disclaim beneficial ownership of all such securities except to the extent of their proportionate pecuniary interests therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Gail A. Sloan,
Attorney-in-fact for
Nader J. Naini</signatureName>
        <signatureDate>2007-04-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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