Deposition of Ag on TiO2 surface by photodeposition method improved the photooxidation rate of benzene in air by inhibiting the build-up of intermediate compounds on the catalyst surface. Although the reaction rate decreased with the increase in benzene concentration, the decrement of reaction rate became smaller by Ag deposition. The selectivities to CO2 and CO were 95 and 5%, respectively, which were almost independent of Ag loading and benzene conversion.