The thin film electroluminescence devices based on Gd 3Ga 5O 12 :Ag were prepared by electron beam evaporation.The component and the crystallinity of phosphor are determined by X ray diffraction.We have obtained a good UV Blue EL emission with a peak at 397 nm and a shoulder at 467 nm.By investigated the absorption spectra and photoluminescence.we conclude that the electroluminescence spectra located at 390 nm and 467 nm are originated from the oxide vacancies and 4d 95s 0 to 4d 10 of Ag +,respectively.