Aluminium nitride AlN(100) thin films have been successfully deposited on Si(111) substrates by reactive magnetron sputtering technique. The films have been characterized by XRD to determine their crystalline preferential orientation. The results show that the experimental parameters including total pressure of working gas(N 2+Ar), N 2 partial pressure, target power and the distance from target to substrate affected crystal orientation, deposition rate, and grain size of AlN thin film. The effects of sputtering time and the substrate temperature on AlN film structure have also been investigated. The optimum experimental parameters for AlN(100) thin film deposition are given. The films have been characterized by XRD to determine their crystalline preferential orientation. The results show that the experimental parameters include total pressure of working gas (N2 + Ar), N2 partial pressure, target power and distance from target to substrate affected crystal orientation, deposition rate, and grain size of AlN thin film. The effects of sputtering time and the substrate temperature on AlN film structure The optimum experimental parameters for AlN (100) thin film deposition are given.