Abstract: Zn_0.85Mg_0.13Al_0.02O thin films have been deposited on Si（111） substrates at temperatures ranging from room temperature to 700℃ by radio frequency magnetron sputtering. The influence of growth temperatures on the micorstructure,morphology and photoluminescence properties of thin films was investigated by X-ray diffraction（XRD）,atomic force microscopy（AFM） and photoluminescence （PL） measurement at temperature room. The results indicate that the thin films have hexagonal wurtzite single phase structure,strong violet photoluminescence peaks（397nm） and weak blue photoluminescence peaks（486nm）.We assign that the violet peaks derived from free excition radiation recombination,blue photoluminescence peaks originated from Zn vacancy and Zn interstitial defects. All films show 75%-95% optical transmission in the visible range.With increasing growth temperature the intensities of the XRD （002） peaks increase,thin films have a prefered orientation with the c axis perpendicular to the substrate,surface roughness,intensities of violet photoluminescence peaks and optical transmission also increase.The optical band gap energies determinded from the obtained transmittance spectras are 3.18,3.18,and 3.19eV. It demonstrates that high quality Zn_0.85Mg_0.13Al_0.02O thin films deposited by RF magnetron sputtering can be obtained by properly controlling the substrat temperature.