Montmorillonite　was　used　to　prepare　organobentonites.　It　was　modified　with　a　suitable　organ-layer　and　made　a　super　organoclay.　The　melting　PVC　polymer　was　intercalated　into　the　organoclay　layer　by　intercalation　for　the　lipophilicity　of　PVC,　and　the　layers　of　montmorillonite　would　be　exfoliated　to　nano-granule　and　dispersed　into　PVC.　Finally,　nanocomposites　could　be　achieved.　The　results　show　that　the　mechanical　properties　of　PVC-U/layered　silicate　nanocomposite　pipe　are　improved　greatly,　and　the　optimal　quantity　of　montmorillonite　is　3%~6%　of　PVC.　FT-IR　and　XRD　were　used　to　characterize　the　structure　of　montmorillonite　and　organobentonites,　which　proved　that　montmorillonite　is　dispersed　into　PVC　evenly.　At　the　same　time,　the　TGA　shows　that　the　heat-resistant　property　of　PVC　is　enhanced　with　the　accession　of　montmorillonite.