A higher hardness carburized layer was formed on the surface of purity titanium by a double glow plasma hydrogen-free carburizing technique depending on glow discharge and hollow cathode effect. High purity solid graphite was used as a source cathode and purity titanium was used as the cathode materials. Experimental results indicate that higher hardness TiC phase and dissociate state carbon antifrictionphase were formed in the carburized layer. The carbon concentration and the hardness of carburized layer distribute in the gradient along the carburized layer from the surface to the inner. The surface hardness increases more than two times. Friction coefficient of Ti materials treated by hydrogen-free carburizing reduces by about 1/2.