Improving　the　properties　and　behaviors　of　polymeric　materials　is　significantly　important　both　in　industry　and　academic　area.　In　this　contribution,　natural　rubber　(NR)　and　ethylene-vinyl　acetate　copolymer　(EVA)　based　nanocomposites　were　prepared　using　polyhedral　oligomeric　silsesquioxane　(POSS)　intercalated　rectorite　(POSS-REC)　as　the　nanofiller.　The　microstructure　and　POSS-REC　dispersion　in　the　composites　were　investigated　via　XRD　and　TEM.　The　results　indicated　that　intercalated-exfoliated　POSS-REC/NR　composites　and　exfoliated　POSS-REC/EVA　composites　were　obtained　successfully.　Thermal　properties　data　indicated　that　the　presence　of　POSS-REC　improved　thermostability　of　the　composites.　SEM　observations　of　fracture　surfaces　showed　that　POSS-REC　in　the　composites　could　terminate　primary　crazings　and　induce　new　smaller　crazings.　Mechanical　tests　showed　that　tensile　strength　and　elongation　at　break　of　the　composites　increased　notably　with　the　content　of　POSS-REC.　On　the　basis　of　experimental　data,　a　possible　dispersion　model　was　proposed.　The　obtained　nanocomposites　may　have　excellent　prospects　in　the　fields　demanding　high　performances.　POLYM.　COMPOS.,　38:E443–E450,　2017.　©　2015　Society　of　Plastics　Engineers.　©　2015　Society　of　Plastics　Engineers