TiO₂/ZrO₂ and TiO₂/ZrO₂/Ce₂O₃ composite thin films deposited on glass substrate were prepared by sol-gel method and characterized by Ultraviolet-visible spectroscopy, scanning electron microscopy (SEM ). The photocatalytic efficiency and the anti-inactivation stability of TiO₂/ZrO₂ and TiO₂/ZrO₂/Ce₂O₃ fillms were tested by degradating methyl orange solution, which was carried out at different uime under ultraviolet light and sunlight respectively. The results showed that the grain size in TiO₂/ZrO₂/Ce₂O₃ thin film doped with Ce³⁺ was smaller and the homogeneity of grain size distribution was higher than that of TiO₂/ZrO₂ thin film. And the TiO₂/ZrO₂/Ce₂O₃ film had a homogeneous grain size distribution and high grain density on surface. The photocatalytic property and anti-inactivation stability of TiO₂/ZrO₂/Ce₂O₃ thin film were all better than that of TiO₂/ZrO₂ thin film. （From : No.3, 2006 Glass & Enamel )