The　possibility　of　obtaining　relatively　high　thermal　conductivity　and　dielectric　constant　but　low　dielectric　loss　polymeric　composites　by　incorporating　the　core-shell-structured　aluminum　(Al)　particles　in　a　linear　low-density　polyethylene　(LLDPE)　by　melt　mixing　and　hot　pressing　was　demonstrated　in　this　study.　The　morphology,　thermal　and　dielectric　properties　of　the　composites　were　characterized　using　X-ray　diffractions,　thermal　analysis,　scanning　electron　microscope,　and　dielectric　analyzer.　The　Al　particle　decreases　the　degree　of　crystallinity　and　has　no　appreciable　influence　on　the　melting　temperature　of　LLDPE.　The　thermal　conductivity,　dielectric　constant　and　loss　factor　of　the　composites　increase　with　an　increase　in　Al　content　at　all　the　frequencies　(1　similar　to　10(6)　Hz).　The　thermal　conductivity　and　dielectric　constant　of　the　70　wt%　flaky　Al　particles　filled　LLDPE　are　1.63　W/mK　and　50,　much　higher　than　those　of　the　spherical　Al　reinforced　one.　Moreover,　the　surface　treatment　of　Al　particles　with　gamma-Aminopropyltriethoxysilane　silane　coupler　improves　the　thermal　conductivity.　The　dielectric　loss　factors　of　the　composites　still　remain　at　relatively　low　levels　in　the　measured　frequency　range.　Further,　the　dielectric　permittivity　frequency　independence　in　the　measured　frequency　range　was　observed　due　to　the　nanoscale-Al-oxide　insulating　shell　of　Al.　POLYM.　ENG.　SCI.,　51:917-924,　2011.　(C)　2011　Society　of　Plastics　Engineers