Abstract: The Mo surface modified layer on Ti6Al4V substrate is obtained by plasma surface alloying. The structure and composition of the Mo surface modified layer are investigated by X-ray diffraction (XRD) and glow discharge optical emission spectroscopy. The duplex Mo modified layer contains a pure Mo coating on subsurface and diffusion layers between the subsurface and substrate. XRD analysis of the Mo modified layer reveals that a Mo phase exists in the modified layer with <110> and <211> orientations in the subsurface. Corrosion-wear behaviors of Ti6Al4V substrate and Mo modified Ti6Al4V alloy sliding against corundum are investigated with the wear-electrochemical noise technique in a 0.5mol/L NaCl solution. Results indicate that the Mo modified layer improves the antiwear and friction reduction properties of Ti6Al4V. Moreover, the Mo modified layer improves self-corroding electric potentials and decrease the current of Ti6Al4V. The Mo modified layer can improve the corrosion-wear behavior of Ti6Al4V.