Polycrystalline Ga2O3 and Cudoped Ga2O3 thin films are prepared by RF magnetron sputtering and N2 ambient annealing. The Xray diffractometer, UVVIS spectrophotometer, fluorescent spectrometer are used to characterize and analyze the structural and optical properties. The experimental results show that the crystal quality deteriorates, the transmittance decreases, the absorption increases, and the effective optical band gap shrinks for Ga2O3 films with Cu impurity doping. The UV, blue and green characteristic emission bands of intrinsic Ga2O3 films are observed. The UV and blue emission are enhanced by Cudoping and a new emission peak centred at 475 nm appears for the Cudoped Ga2O3 films.