Cuprous oxide (Cu₂O) thin films were prepared on ITO conductive glass substrates by pulse magnetron sputtering,using a metallic copper target in Ar and O_2mixture atmosphere.Effe cts of sputtering pressures on crystalline structure,surface morphology and optical properties of Cu₂O thin f ilms are investigated.The results show that the thin films deposited with an O₂/Ar flow ratio of 20∶90are p ure phase Cu₂O for 2-3Pa sputtering pressures.The surface morphology of Cu₂O thin films depends on the sputtering pressures,and the root mean square (RMS) values of surface roughness of the thin films decr ease with increasing sputtering pressures.After a Cu₂O layer was deposited on ITO substrate,th e absorption edge red shifts to ～780nm,the absorption intensity of ITO/Cu₂O composite films increases with increasing sputtering pressures in the wavelength range of 300－780nm,and the optical band gap (E_g) values of thin films deposited a t different sputtering pressures range from 2.28eV to 2.39eV.