Abstract: Ag/TiO2 film was prepared by photochemical reduction method with depositing Ag nanoparticles on TiO2 surfaces. The influence of TiO2 annealed at different temperatures on the photocatalytic deposition of Ag nanoparticles was analyzed by ultravioletvisible (UV-Vis) absorption spectra, and TiO2 films annealed at 500℃ were helpful to the reduction of Ag nanoparticles. By the 650 nm red laser irradiation, Ag/TiO2 films annealed at 500℃ exhibited photochromic properties well. The mechanisms of photochromism were studied, and we found the response rate of photochromism of Ag/TiO2 films improved with the increase of Ag depositing time, but excess Ag nanoparticles inhibited the photochromic response rate of the Ag/TiO2 thin film.