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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 OfnvknpEYtPahxGBcQpR2DS8tRUMDHCuuMx/lNAFTAhR9j4vYf3Y0SYtZNPA5gqO
 QHbQhdpTLU5g4QfVmnmhCQ==

<SEC-DOCUMENT>0001021075-03-000001.txt : 20030522
<SEC-HEADER>0001021075-03-000001.hdr.sgml : 20030522
<ACCEPTANCE-DATETIME>20030522170309
ACCESSION NUMBER:		0001021075-03-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030521
FILED AS OF DATE:		20030522

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LANDSTAR SYSTEM INC
		CENTRAL INDEX KEY:			0000853816
		STANDARD INDUSTRIAL CLASSIFICATION:	TRUCKING (NO LOCAL) [4213]
		IRS NUMBER:				061313069
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1226

	BUSINESS ADDRESS:	
		STREET 1:		13410 SUTTON PARK DRIVE SOUTH
		CITY:			JACKSONVILLE
		STATE:			FL
		ZIP:			32224
		BUSINESS PHONE:		9043901234

	MAIL ADDRESS:	
		STREET 1:		LANDSTAR SYSTEM INC
		STREET 2:		13410 SUTTON PARK DRIVE SOUTH
		CITY:			JACKSONVILLE
		STATE:			FL
		ZIP:			32224

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MOTT MERRITT J
		CENTRAL INDEX KEY:			0001021075
		STANDARD INDUSTRIAL CLASSIFICATION:	TRUCKING (NO LOCAL) [4213]
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21238
		FILM NUMBER:		03716748

	BUSINESS ADDRESS:	
		STREET 1:		C/O BLACKHAWK STATE BANK
		STREET 2:		400 BROAD ST
		CITY:			BELOIT
		STATE:			WI
		ZIP:			53511
		BUSINESS PHONE:		6083648911

	MAIL ADDRESS:	
		STREET 1:		C/O BLACKHAWK BANK
		STREET 2:		400 BROAD ST
		CITY:			BELOIT
		STATE:			WI
		ZIP:			53511
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001021075d20030522f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<ownershipDocument><schemaVersion>X0101</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-05-21</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000853816</issuerCik><issuerName>LANDSTAR SYSTEM INC</issuerName>        <issuerTradingSymbol>LSTR</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001021075</rptOwnerCik><rptOwnerName>MOTT MERRITT J</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>  </rptOwnerStreet1><rptOwnerStreet2>  </rptOwnerStreet2><rptOwnerCity>  </rptOwnerCity><rptOwnerState>  </rptOwnerState><rptOwnerZipCode>  </rptOwnerZipCode></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle></officerTitle><otherText></otherText></reportingOwnerRelationship></reportingOwner><nonDerivativeSecurity><securityTitle><value>Common Stock</value></securityTitle><transactionDate><valu
e>2003-05-21</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>200</value></transactionShares><transactionValue><value>57.9</value></transactionValue><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By trust of daughter</value><footnoteId id="F1"/></natureOfOwnership></ownershipNature></nonDerivativeSecurity><footnotes><footnote id="F1">Mr. Mott is trustee of daughter's trust.  In addition, Mr. Mott holds 12,600 shares of common stock directly.</footnote></footnotes><ownerS
ignature><signatureName>Robert C. LaRose</signatureName><signatureDate>2003-05-22</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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