CdS + ZnTiO3 and ZnTiO3 nanocomposite film were prepared by sputtering process. Photocatalytic activity of CdS + ZnTiO3 nanocomposite film is higher than ZnTiO3 film. The improvement of photocatalytic activity was attributed to the band gap coupling. Structural, morphologic and optical properties of the nanocomposites were studied.