Nanostructured silver thin films irradiated by atomic oxygen (AO) generated in a ground simulation apparatus were investigated by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). AFM results show that after irradiation, all the grain sizes of the thin films became more or less small, and the compact surface became rough and sparse. From XPS depth profile of an AO-irradiated silver thin film, it can be found that the silver oxides formed exist as two valences, that is, at the surface, the oxide is mainly AgO, and gradually change to Ag 2 O, the content of unoxidized silver also increase with depth of film.