Abstract: Well spatial-dispersed and high purity silver oxide nanoparticles, whose size can be controlled from 5 nm to 30 nm, were prepared by vacuum thermal evaporation and glow discharge oxidation. To form island and keep samples in darkness are two key points of synthesis. Based on Ag3d and O1s binding energy and the ratio of silver atoms to oxide atoms given by XPS, the sample was confirmed to be Ag2O. X-ray diffraction of Ag2O nano-scale thin films was acquired and the strongest diffraction peaks referred to face (111), (110), (200) and (211) of Ag2O. Absorption spectra of the samples were also studied. The absorption spectrum indicates that band gap of silver oxide is 2.8 eV. After being photo-activated by blue light for a few minutes, intermittent green and yellow photoluminescence from silver oxide nanoparticles were observed with blue excitation. Luminescence from the same region excited by green light is red and also dynamic. This phenomenon was explained by electron transitions to the impurities energy levels induced by photolytic centers（Ag3O, Ag2＋O and Ag3＋O） in silver oxide.