The preferential c-axis oriented (002) AlN thin films were prepared by direct current (DC) reactive magnetron sputtering technique on ZnO/Si substrates. X-ray diffraction (XRD) and atomic force microscope (AFM) were employed to characterize the morphology and structure of the films deposited at different substrate temperature. The results showed that within a certain range of temperature(450 650 ℃), the crystal grain size, deposition rate increased and surface roughness decreased firstly and then increased with the substrate temperature increase. The c-axis orientation became better, the degree of orientation of the A1N thin films increased at the beginning and then decreased with substrate temperature increase, and the orientation became optimal at 600 ℃.