Abstract: LY12CZ(2024) aluminum alloy was studied by Plasma Immersion Ion Implantation(PIII) technique.Chemical composition,valences of various elements,friction and wear behavior and concentration-depth distribution of different elements were analyzed,respectively.X-ray photoelectron spectroscopy(XPS) results reveal that aluminum nitride(AlN) phase exists in the surface modified layer.Compared with the substrate,the microhardness of treated sample is increased with maximum by 1.4 times,friction coefficient decreased obviously,and wear mass loss are decreased significantly with maximum loss by 75%.The overall surface properties are improved greatly.