Ti3AlC2 samples are irradiated in advance by 3.5 MeV Fe-ion to the fluence of 1.0× 1016 ion/cm2,and then are implanted by 500 keV He-ion with the fluence of 1.0× 1017 ion/cm2 at room temperature.The irradiated samples are investigated by grazing incidence x-ray diffraction (GIXRD) and transmission electron microscopy (TEM).GIXRD results show serious structural distortion,but without amorphization in the irradiated samples.Fe-ion irradiation and He-ion implantation create much more serious structural distortion than single Fe-ion irradiation.TEM results reveal that there are a large number of defect clusters in the damage region,and dense spherical He bubbles appear in the He depositional region.It seems that the pre-damage does not influence the growth of He bubbles,but He-ion implantation influences the pre-created defect configurations.