Localized Surface Plasmon Resonance(LSPR) was widely used in photocat alysis and solar cells fields.The Ag@SiO₂/TiO_2thin films were deposited on fuse d quartz and Si substrates employing electron beam and thermal evaporation techn ique followed thermal annealing in air atmosphere at 300℃,400℃,500℃,600℃ for two hours.The prepared samples were characterized with the Raman spect rometer,UV-Vis spectrophotometer for microstructure,optical,respectively.Th e composition and content of elements were determined by energy dispersive spect rometer.The photocatalytic activity of synthesized thin films were evaluated for degradation of methyl orange in aqueous solution.Results indicated the as-dep o sited films (250℃) have amorphous nature;with the increase of the annealing t e mperature,the film is in the anatase structure base on the condition of this exp eriment.while films annealed at 400℃－600℃ show polycrystalline in nature.An atase phase presents better photocatalytic performance.