Abstract: Needle-shaped nano-calcium carbonate was modified and was introduced into polyvinyl chloride (PVC) materials, the mechanical properties of the composite were studied. The tensile and impact strengths of the composite containing 5 % modified nano-calcium carbonate increased by 5 and 10 %, respectively, compared with un-filled PVC. Scanning electron micrograph (SEM) showed that the dispersion of the modified nano-calcium carbonate was uniform，fracture surface showed a ductile mode.

Key words: needle-shaped nano-calcium carbonate, surface modification, poly(vinyl chloride), mechanical property