Aluminum nitride (AlN) thin films have attracted much attention because of its more excellent properties and are widely applied to different fields. In our work, AlN thin films were grown on silicon substrate bying using D.C. magnetism filter arc deposition. Various annealing temperature of 573K, 773K, 973K, 1173K were used to process AlN thin films. Microscopy, ellpsometry and XRD were carried out to character films' properties. The results show that the films' refractive index and the extinction coefficient, processed in different annealing temperature, presented small float and were all less than 5 X 10-3, respectively. Furthermore, from microscopy graph, we can see that the film, annealed in 573-973K temperature, were all un-cracked, uniformity and denser. However, the films show cracking when the annealing temperature reaches 1173K°C. In addition, the XRD spectrum of AlN films show 002 preferred orientation with 973K annealing temperature and show abroad band peaks without annealing.