Abstract: With methyl vinyl silicone as the base rubber, filled with carbon coated aluminum(C-Al) nanoparticles, the heat dissipation composites were prepared by using the method of mechanical blending. The SEM was employed to analyze the dispersion of C-Al nanoparticles disperse in silicone rubber which showed that the nanoparticles uniform distribution in silicone rubber. The effect of C-Al nanoparticles on thermal conductivity and coefficient of thermal expansion (CTE) of the silicone rubber were investigated, and it was found that thermal conductivity of the composite increases with increasing the C-Al nanoparticles content, the thermal conductivity begins to decrease when the C-Al volume fraction reaches 50%. The optimum filling amount of C-Al nanoparticles is 50%. The CTE decreases with the loading increasing. TGA shows that the addition of C-Al nanoparticles increases the thermal stability of the silicone rubber.