Abstract: Calcium carbonate is one the most important inorganic powdery additives applied in the plastic processing.Summarized the important role of calcium carbonate in plastics；introduced the basic requirements of plastic processing on calcium carbonate (price，white content，granularity and particle size distribution etc.)；studied the surface treatment of nano-sized calcium carbonate and introduced several surface treatment agents and equipment；primarily studied the application of nano-sized calcium carbonate in plastic as well as its dispersion in matrices；finally taking calcium carbonate using as plasticizer for HDPE special material and calcium carbonate-photodegradable plastic as examples，introduced the application progress of calcium carbonate in plastic processing industry.