Abstract: By means of SEM with Ultra-Microhardnesstester, loads ranging from 2g to 0.05g were put on the HgCd Te wafers of different orient ations. Because of the anisotropic propert ies of cryst al, the same load results in varying degree of damage on differently oriented wafers. The experiment results showed that the damage area was decreasing with orientations of the HgCdTe wafer as following: 111＞121＞351. The structure of damage layer was discussed as well.