CuO/SiO2 nanocomposite films were prepared by sol-gel process combined with the dip-coating technique. The mean diameter of CuO nanoparticles formed during the heat treatment process and mainly lay in the pores of mesoporous SiO2 matrix increased by increasing the heat treatment temperature. Consequently, compared with mesoporous SiO2 matrix, the pore volume and specific surface area of prepared samples descend. The diffraction peaks of Cu and CuO and the crystalline diffraction ring of CuO with body centered cubic structure can be clearly observed after heat-treated in air and H2 at 800 oC for 1h. By increasing the heat treatment temperature and concentration of CuO, a slightly red-shift could be observed.