ToimprovethewatertreeresistanceofPE,linearlow-densitypolyethylene(LLDPE)wascompoundedwithsodiumacrylate(NaAA)forinsitupolymerization,inwhichNaAAwasformedthroughtheneutralizationofacrylicacid(AA)withsodiumhydroxide(NaOH)beforeaddingdicumylperoxide(DCP)toinitiatetheinsitugraftpolymerizationandhomopolymerization.AseriesofLLDPE/NaAAcompoundswereinvestigatedfortheirwaterabsorptionratio(WAR)measurement,watertreeing,mechanicalanddielectricproperties.TheresultsstronglysuggestthatNaAAcanimprovethewatertreeresistanceofLLDPE.Inaddition,theLLDPE/NaAAcompoundspossesssatisfactorymechanicalpropertiesanddielectricproperties.CharacterizationofLLDPE/NaAAcompoundsbyusingFouriertransforminfraredspectrometry(FTIR)suggeststhattheneutralizationandpolymerizationreactioncouldbeachievedeffectively.UsingadequateDCPcontentisthekeyfactorforcontrollingthepolymerizationofNaAAwithpreciseconversionratio.