Thermal and mechanical properties of CPVC(chlorinated PVC) are better than those of PVC. CPVC was blended with PVC to increase properties of PVC fiber. Blending ratio of CPVC was changed and thermal, rheological and mechanical properties were investigated in this study. Thermal stability and melt viscosity increased with increase in CPVC content. Fiber was spun by melt spinning method and drawn using heat plate. Tenacity increased and elongation decreased with increase in CPVC content. Heat shrinkage decreased with increase in CPVC content and heat treating temperature. Onset temperature of DSC endotherm peak corresponded to the treated heat temperature.