Abstract: Lubrication characteristics of polyethylene wax and calcium stearate (CaSt2) for poly(vinyl chloride) (PVC) were investigated by measuring plasticizing time with a torque rheometer. The results indicated that polyethylene wax acted an effective primary resin external lubricant for PVC, and CaSt2 acted as an effective secondary resin external lubricant. There was a significant synergistic effect when these two lubricants were combined. The external lubricating performance of polyethylene wax and its combination with CaSt2 was enhanced with an increase of total amount of two lubricants, in which the fraction of polyethylene wax was fixed as 1 phr. The lubrication mechanisms can be deduced as follows: when the lubricant is used alone, polyethylene wax can spread over and wet the PVC particles to prevent them from contacting directly and friction with each other, but CaSt2 cannot wet PVC particles due to the formation of agglomerations and reverse micelles. On the other hand, the combination of these two lubricants can make CaSt2 dissolved slightly in polyethylene wax and then absorbed on the interface between PVC particles and polyethylene wax. As a result, the direct contact and friction between the PVC particles can be prevented effectively.