Abstract: The mechanochemical surface modification of two-dimension sericite flaky nano-materials was investigated through the grinding of a stirred mill. With titanite as the surface modification agent of sericite, the effects of the dosage of modification agent, massic ratio of midium/sericite, density of slurry, grinding time, temperature and pH value on the surface modification were analyzed. The properties of polypropylene (PP) filled with the modified filler were tested. The result shows that it is feasible to modificate two-dimension sericite flaky nano-materials mechnochemically and the composite materials of PP filled with the modified filler have a better capacity of resisting ultraviolet radiation.