The intermittent vacuum gas nitriding (IVGN) process was introduced to improve the surface properties of TB8 titanium alloys. The phase constitution and microstructure of the surface-modified layer were measured by XRD and SEM, and the surface hardness and wear resistance of the treated samples were analyzed. The results indicated that a surface-modified layer composed of TiN, TiN_0.3, and Ti₂AlN was formed after IVPN treatment at 800 ℃ for 4 h. The microstructure of modified layer was dense and had a good bonding with its substrate. The surface hardness of treated samples was up to 850-900 HV, which was three times as much as that of the untreated samples. The thickness of hardened layer was about 80-100μm. The wear resistance was greatly improved due to the formation of a gradient hardened layer.