Abstract: The effect of primary heat stabilizer，auxiliary heat stabilizer, inner lubricant，and external lubricant on the processability，thermostability and mechanical properties of chlorinated Poly（vinyl chloride）（CPVC）was studied. It showed that the processability and the thermostability were best when the primary stabilizer was 3.0 phr，auxiliary heat stabilizers Pb-St and Ba-St were 0.7~1.1 phr each, inner lubricant H-St was 0.5 phr, external lubricant petrolin was 0. 6 phr. The impact strength，tensile strength，and Vicat softening point were 20. 19 kJ/m2， 67. 36 MPa，122. 3℃，respectively.

Key words: chlorinated poly(vinyl chloride), heat stabilizer, lubricant, rheology, processability