TiN thin films were deposited on Si(111)substrates under different N2/Ar flow ratio by DC reactive magnetron sputtering method, in order to quantify the growth orientation of TiN film. The orientation, phase structures, morphology of TiN thin films were characterized. The effect of N2/Ar air pressure on orientation of TiN thin films was investigated, and the relations between TC and thin films morphology were analyzed. The results show that when the N2/Ar air pressure is less than 1：30,the phase structure evolves from the orientation(200) to (111).(111)structural surface of thin film uniformity, denser and roughness smaller, film-substrates combined with better, and the best one is the 1.63 orientation film when the N2/Ar flow ratio is 1：60.