AlN and TiN thin films are widely used in electronic devices and acoustic material and other fields because of its unique merit, the preparation of nitride thin films by using the arc ion plating has not been a systematic and deep study. The article presents our research procedure which the AlN and TiN thin films are deposited on stainless steel substrate by arc ion plating (AIP). The characteristics of thin films, for example microstructure, morphology, composition analysis and hardness, are examined and analyzed. The results showed that: Droplet-like particles appear in the microstructure of nitride thin films, and the grain size of droplet-like particles in AlN thin films is greater than in TiN thin films. The micro-hardness of nitride films preparation in experiment has improved significantly, and establish firmly basic for extending the application field of nitride film.