The Mo coatings prepared by glow plasma deposition on TC4 titanium alloy were sulfurized at 650 ℃ . Microstructure, hardness and tribological properties of the sulfurized Mo coatings were studied. The results reveal that the surface microstructure of the original Mo coating is refined and the surface hardness reduces after sulfuration treatment . The composites formed on the substrate surface are mainly MoS₂and some Mo₂C and Ti₂S. The wear rate of the coating is about 1 / 10 of the TC4 wear rate.