Mo modified layers on pure Ti surface were obtained by using the plasma surface alloying technique. The composition and phase structure of the Mo modified layer were characterized. Dry sliding properties of the Mo modified layer were investigated by reciprocating sliding wear tester. The results indicate that the layer is a duplex layer, which contains a deposition layer and a diffusion layer. The thickness of deposition layer and diffusion layer increase with the increase of treatment temperature, and the Mo modified layer can obviously improve the wear resistance of pure Ti.