The Aldoped ZnO (AZO) films were prepared by the RF magnetron sputtering method. The AZO films were characterized by X-ray diffraction, atomic force microscopy, four probes. The effects of different heat treatment temperature on the morphology, structure and electrical properties of AZO thin films were investigated. The results showed that the film particles were uniform and the diffraction peak intensity of AZO film was first enhanced and then weakened with the increase of the heat treatment temperature when the Al doping volume fraction was about 1.2%. When the heat treatment temperature was 450 ℃, the crystallinity of the AZO film was the best and the minimum resistivity was 0.024 7 Ω·cm.