Abstract: Using natural sericite mineral as raw material，through crashing and surface chemical modification，the ultrafine sericite powders were obtained. The excellent liquid silicone rubber reinforced by ultrafine sericite was；prepared through solution polymerization.The microstructures and properties of composities were investigated by SEMbecause the surface of sericite particles was modified with organic functional groups，they can disperse in the silicone rubber perfectly. The mechanical properties of composites，such as tensile strength and hardness(Shore A)are improved prominently. Compared to silicone rubber unreinforced，when the mass fraction of ultrafine sericite was 8%，tensile strength and hardness(Shore A ) have improved 197.62% and 48.78%. The result of TGA shows that the thermal stability was superior to that of silicone rubber without any fillers. The interaction between ultrafine sericite and silicone rubber was characterized by the Kraus equation. The Kraus curve shows that there is interaction between ultrafine sericite and silicone rubber.