ABSTRACTIn this research, ZnO:Ag thin films have been successfully deposited on glass substrates by spray coating technique with a variety of the doped of percent Ag about 2%, 3%, 4% dan 5%.. Optical properties ZnO:Ag thin films were characterized by using UV-Vis spectroscopy. Methylene blue as degradation media was used to estimate the photocatalytic activity from deposition samples ZnO:Ag . The research showed that silver doped in ZnO can enhance photocatalytic actifity because inhibite the recombination rate. In addition, higher concentration of ion doped, lower band gap energy making electron easily excitate. The result photocatalityc activity of ZnO:Ag able to degrade Methylene blue until 91,37%Keywords: Photocatalyst, Spray coating, ZnO:Ag, Band gap energy, Methylene blue.