Investigates the influence of Al-doped on the structure and optical properties of ZnO(ZAO) thin films which prepared by direct current (dc) magnetron sputtering. The X-ray diffraction results reveal that the film has good C-axis preferred orientation growth characteristics, the substrate temperature influences obviously on the optical transmittance and photoluminescence (PL) spectra of both ZnO and ZAO films, and all films exhibit a transmittance higher than 86% in the visible region, while the optical transmittance of ZAO films is slightly smaller than that of ZnO films. Al-doping leads to a larger optical band gap (Eg) of the films, the near-band-edge (NBE) emission and deep-level (DL) emission are observed in pure ZnO thin films by PL measurement, however the DL emission of the thin films is depressed with Al-doping. As the substrate temperature increases, the peak of NBE emission has a blueshift to region of higher photon energy, which shows a trend similar to the Eg in optical transmittance measurement