Mid frequency (MF) reactive sputtering is a potential technique for dielectric films preparation. In this study, different orientations of aluminum nitride (AlN) films were grown on silicon substrates by MF reactive sputtering. The process parameters such as substrate-to-target spacing, chamber pressure, sputtering power, and N2 concentration on the film growth were investigated. The results reveal that higher power, shorter substrate-to-target distance, lower sputtering pressure, and lower N2 ratio advantage the formation of [0 0 2] texture. The film quality is good and the growth rate is faster than those by RF sputtering technique. The mechanism for formation of different preferred orientations in AlN films is discussed.