In order to study the effect of Ag content on photocatalytic efficienc y,Ag-doped TiO_2coatings were deposited by electron beam evaporation.The structural,optical,morphology an d elemental compositions of the obtained nanocomposites were characterized using the X-ray diffraction (XRD), ultravidet-visible (UV-Vis) spectrophotometer, scanning electron microscopy (SEM),atomic force microscopy (AFM) and X-ray ph otoemission spectroscopy (XPS),respectively.The photocatalytic activity of Ag/TiO_2was me asured by using photocatalytic oxidation of MO as a model reaction,and the effect of Ag concentration on the p hotocatalytic activity was investigated.It is found that the Ag is in the Ag^0state.The silver nanoparti cles are uniformly distributed and strongly attached to the mesoporous TiO_2matrix.The Ag-TiO_2films is amorph ous at 300℃.The photocatalytic activity of TiO_{2nanoparticles} can be improved by depositing appropriate a mount of silver.