This paper deals with the formation of AIN thin films successfully deposited on Si(III) substrates by using the direct current magnetron sputtering method. The films feature planes with (100) and (002) preferential orientations, low surface roughness and a homogeneous composition. The effects of the sputtering pressure, sputtering power and distance (D) from the target to the substrate on the preferential orientation of the ALN films are also studied. The results show that a lower sputtering pressure and shorter distance D are conducive to the formation of the (002) plane. On the contrary, a higher sputtering pressure and longer distance D are beneficial for the growth of the (100) plane. Moreover, the preferential orientation of the ALN thin film is also dealt with from the viewpoint of the formation of the Al-N chemical bond and the mean free path of sputtered particles.