Ga2O3 thin films were grown on quartz substrate by radio-frequency magnetron sputtering. The structure and optical bandgap of Ga2O3 films were characterized by X-ray diffraction and UV-Vis-IR spectroscopy, respectively. The photoluminescence (PL) spectra of Ga2O3 films were measured at room temperature. The results show that the deposited Ga2O3 films are amorphous. As the pressure increases, the optical absorption edge firstly shows blue shift and then switches to red shift. The optical bandgap value ranges from 4.96 to 5.30eV. When the sputtering pressure is 1Pa, the deposited Ga2O3 film has the largest optical band gap. Under the excitation of 325nm laser, luminescence peaks related to defect energy levels appear near 400 and 525nm.