Abstract: Single crystal silicon<111>wafer was implanted by carbon ions with the dose of 2×1016 ions·cm-2 and energy of 60 keV and 80 keV,respectively.Crystal structure changes of the silicon wafers before and after carbon ion(C+)-implantation were observed by X-ray diffractometer.Then the fretting wear tests were performed on a UMT-2 micro-tribometer,and the wear depth,wear morphology and the wear mechanism were analyzed with high-accuracy 3D profiler and S-3000N scanning electron microscopy.The results show that crystal structure of the silicon vafers was changed by C+-implantation which made the crystal disordered.The friction coefficient and wear depth of the silicon wafers increased with the increase of the load and fretting amplitude,and the friction-reducing effect and wear-resistance of the C+-implantation silicon wafers were obviously improved.When the load reached a certain value,carbon ion implanted layer was worn out gradually as the prolongation time,the friction coefficient increased rapidly.And the silicon wafers with energy of 60 keV had excellent friction-reducing and wear-resistance properties.The wear traces of the silicon wafers before and after C+-implantation were similar to ellipse,the wear area was small and degree of damnification was mild after inplantation.The main wear mechanism was abrasive wear.