Diamond-like carbon(DLC) films were fabricated on NiTi alloys using plasma immersion ion implantation and deposition(PIIID).The surface morphology and roughness were analyzed by atomic force microscopy(AFM).The film microstructure and hardness were characterized by Raman scattering spectroscopy and nano-indentation system,respectively.The corrosion resistance in Hank's solution was evaluated by mean of potentiodynamic polarization techniques.The surface morphology of the samples was observed using scanning electron microscopy(SEM) after potentiodynamic polarization tests.The Ni ions release from the NiTi alloys was measured by atomic absorption spectroscopy(AAS).It is shown that the roughness and hardness of the NiTi alloys is reduced and increased by DLC film,respectively.The DLC films markedly improve the corrosion resistance of the NiTi alloys and effectively prevent the Ni ions dissolution from the substrate.