Using the double glow plasma metallulgy principle improve the tribological properties of Ti6Al4V. A high pure solid honeycomb graphite was taken as source cathode, titanium alloy Ti6Al4V as cathode, high pure argon and nitrogen gas as working gas, The carbonitriding Iayer with special physical and chemical properties was prepared on the surface of Ti6Al4V. The phase compositions and C. N, Ti distribution in carbonitriding layer were determined by means of XRD and glow discharge spectrometry. The surface layer microhardness distribution was measured gradually from surface to inner. Microhardness of surface increased more than two times. Results from friction and wear test show thai the wear resistance property of TifAl4V alloy is improved evidently.