Four point bending fatigue tests were carried out using martensitic stainless steel with TiN film deposited at five different deposition rates by dynamic ion mixing process in order to investigate the influence of deposition rate on the fatigue strength. As a result, the fatigue limit clearly increased by the deposition at appropriate conditions. However, the deposition by other conditions resulted in the degradation of fatigue strength. This is caused by the decrease of threshold stress intensity factor after TiN deposition and the difference of defect distribution in the film. In addition, the crack propagation rate was increased in low stress intensity factor range by the deposition of TiN film.