-----BEGIN PRIVACY-ENHANCED MESSAGE-----
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,
 G1x4XklI2LHoApYln3LvR6CCDHHtw9huitwseqQAHbLhEevqg3pIOhXrRHFBrA+X
 WWOrlxL530hgGG0KpFBoKQ==

<SEC-DOCUMENT>0001252108-08-000006.txt : 20080401
<SEC-HEADER>0001252108-08-000006.hdr.sgml : 20080401
<ACCEPTANCE-DATETIME>20080401112523
ACCESSION NUMBER:		0001252108-08-000006
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080401
FILED AS OF DATE:		20080401
DATE AS OF CHANGE:		20080401

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			US MICROBICS INC
		CENTRAL INDEX KEY:			0000774454
		STANDARD INDUSTRIAL CLASSIFICATION:	HAZARDOUS WASTE MANAGEMENT [4955]
		IRS NUMBER:				840990371
		STATE OF INCORPORATION:			CO
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		6451 EL CAMINO REAL #C
		CITY:			CARLSBAD
		STATE:			CA
		ZIP:			92009
		BUSINESS PHONE:		7609181860

	MAIL ADDRESS:	
		STREET 1:		6451 EL CAMINO REAL #C
		CITY:			CARLSBAD
		STATE:			CA
		ZIP:			92009

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GLOBAL VENTURE FUNDING INC
		DATE OF NAME CHANGE:	19930621

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	VENTURE FUNDING CORP
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BREHM ROBERT C
		CENTRAL INDEX KEY:			0001252108

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14213
		FILM NUMBER:		08727879

	MAIL ADDRESS:	
		STREET 1:		6965 EL CAMINO ROAD # 105279
		CITY:			CARLSBAD
		STATE:			CA
		ZIP:			92009
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-04-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000774454</issuerCik>
        <issuerName>US MICROBICS INC</issuerName>
        <issuerTradingSymbol>BUGS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001252108</rptOwnerCik>
            <rptOwnerName>BREHM ROBERT C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6965 EL CAMINO ROAD # 105279</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CARLSBAD</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92009</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Common Stock Options</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.001</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-04-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>37500000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.001</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2008-04-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-04-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Restricted Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>37500000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>85926179</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>/s/ Robert C Brehm</signatureName>
        <signatureDate>2008-04-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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