TiN films were deposited onto the NiTi shape memory alloys by an arc ion plating technique. The phase identification and surface characteristics of the specimens were successively performed and tested by X-ray diffraction, scanning electron microscope and atom force microscopy. We investigated and compared compatibility and corrosion properties of NiTi alloys in vitro blood with and without TiN film. Experimental results indicated that the TiN film had improved the blood compatibility and corrosion resistance properties of NiTi alloy, and the release rate of Ni ions was reduced about one magnitude after plated TiN film; the thicker the film was, the more the properties improved.