Chemical by crosslinked PVC was synthesized by vinyl chloride/diallyl phthalate (VC/DAP) suspension copolymerization and processed to prepare plasticized sample. PVC prepared by VC/DAP copolymerization was composed of gel and sol fraction and the crosslinking density of gle was lower. It confirmed that chain entanglements existed in both gel phase and sol phase. PVC still exhibited the recrystallization ability as it was lightly chemical by crosslinked. The structure model of plasticized and lightly chemical crosslink network and physical crosslink network formed by chain entanglements and micro-crystallites were cooperated each other. The rheological

temperature-deformation behavior and permanent compression set of plasticized and lightly chemical by crosslinked PVC were influenced by chemical and physical crosslinking.