Gallium oxide (Ga2O3) thin films were prepared on Si substrate by magnetron sputtering.The obtained samples were comprehensively characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM).Ti,Pt,Ni and AZO were deposited on the Ga2O3 thin films as electrodes.This paper mainly studies the metal-semiconductor contact formed by these four materials on the films and the influence of annealing at 500 ℃ on the metal-semiconductor contact.The Ⅰ-Ⅴ characteristics show a good linear relationship,which indicates ohmic contact between Ga2O3 and other electrodes.