Inthisstudy,weinvestigatedanalyticalproceduresforobtainingaccurateandreliabletotalorganiccarbon(TOC)measurementsinparticle-containingwatersamples.MostTOCvaluesobtainedatseverallaboratoriesforcelluloseparticle-containingsamples(20~100μm,10~100mg-C/L)didnotmeetthequalitycontrolcri-teria(i.e.,80%).Therefore,inthisstudy,theinfluenceofsuspendedparticles(particlesize,andconcentration)onTOCanalyticalprocedures(sampleinjection,purgingtime,washing,dilutionetc.)andTOCmeasurements(accuracyandprecision)wasevaluatedspecificallyforcelluloseparticle-containingwatersamples,andvariousotherenvironmentalsamples(soil,roadsediment,sewagesludge).Resultsofthewashingexperimentshowedthatabouttwicethewashingvolumewasrequired,comparedwiththatrequiredinconventionalTOCanalysisfordissolvedsamples,fortheremovalofresidualparticlesintheapparatusafterthemeasurement.Also,anormalinjectionmethodwaspreferredforsampleinjectionandanappropriatesamplepreparationmethod(withoutdilution)andproperconcentrationranges(10~100mg-C/L)aresuggestedbasedontheresultsofourstudy.