Microwave plasma enhanced CVD with AlBr3-NH3-N-2 system is developed for the preparation of AIN thin films. The growth rate and morphology of the films on Si(lll) substrate as a function of the operation parameters were systematically studied. (002) oriented AIN thin films have been obtained. The growth rate vs, temperature showed a two-regime behavior with activation energies of 3.12 kJ/mol and 15.6 kJ/mol, respectively. The dependence of the growth rate on AlBr3 precursor temperature well fitted the prediction from thermodynamic analysis of the CVD system, indicating the deposition rate limited by the mass feeding process. A surface kinetic model was proposed to interpret the (002) oriented growth behavior.