Abstract: PVC/CaCO₃ composites were prepared by melt blending with calcium carbonate as inorganic filler. The effect of surface modification of calcium carbonate on the properties of the composites was investigated. The surface characteristic of calcium carbonate were characterized by Fourier transform infrared spectroscopy（FTIR） and contact angle test, Omnipotent testing instrument and Scanning electron microscopy（SEM） and other equipment were used to test the macro properties and micro morphology of the composites. The results show that the composites possess better comprehensive properties which with calcium carbonate modified by stearic acid and titanate coupling agent. Compared to its counterpart with unmodified calcium carbonate, its impact strength is increased by 15%.