Abstract: Generally, pure PVC can not be irradiation crosslinked by electron beams or α-rays; crosslinking agents (or sensitizers) must be used in the irradiation crosslinking of PVC. The effect of the different sensitizers on irradiation crosslinking of PVC has been investigated. The kind of sensitizer and its content in PVC influence the thermal stability, mechanical properties and electrical properties of XLPVC. Experimental results show that TMPTMA is a better sensitizer for irradiation crosslinking of PVC. Also, the effect of different sensitizers on the relationship.between the sol fraction (S) and dose (R) is discussed. It is found that the logarithmic value of sol fraction (InS) is proportional to the sensitizer content in PVC.