Abstract: TiN/Ti composite coating was deposited on TC4 titanium alloy substrate with the self-made special gas-filled-closed electric-spark deposition device and electric-spark deposition machine modeled DZ-1400, the industry pure titanium(TA2) was used as electrode and the industry pure nitrogen gas as shielding and reacting atmosphere.The microstructures, interfacial behavior, phase and element in the coatings were investigated by scanning electronic microscope, X-ray diffraction and X-ray photo spectrum.The microhardness of coatings was tested and its wear-resistance property was tested by the self-made abrasion machine and compared with W18Cr4V rapid steel treated by quenching.The results show that an excellent bonding between the coating and substrate is ensured by the strong metallurgical interface.The coatings are mainly composed of Ti and synthesized TiN. The highest microhardness of coating reaches to 1 388 HV0.1, which is six times higher than that of the substrates.Wear resistance of the coatings is excellent.