In order to improve the toughness of polypropylene (PP) and expand its applications, a layer of polyurethane (PU) elastomer was coated on the surface of ultrafine talcum powder by an in-situ synthesis method. In this way, an organic-inorganic composite particle was formed. Then the surface-treated talcum powder was mixed with melted PP to prepare PP composite materials through extrusion, granulation, and injection molding. Infrared spectral characterization and energy-dispersive X-ray analysis showed that there was a layer of PU elastomer on the surface of the talcum powder. Impact fracture analysis indicated that there was good compatibility between the talcum powder and the PP matrix. With the incorporation of PU elastomer coated on the surface of talcum powder, the toughness of PP was significantly improved, while the tensile strength decreased slightly. The optimum properties of the composite material were obtained when the weight fraction of talcum powder was 20% and the PU coating coverage was 25%. J. VINYL ADDIT. TECHNOL., 16:64-69,