A new process for fabricating of SiC/SiC composite, the Nano-powder Infiltration and Transient (NITE) method produces dense, high strength SiC materials with potential applications in fission or fusion reactors. Irradiation effects reduce the performance of materials due to accumulation of point defects. In this research, SiC/SiC composite fabricated by the NITE process was irradiated with Si-ions. Post-irradiation investigation was performed by TEM. The ion-irradiation experiments were performed using a 1.7 MeV tandem accelerator at DuET facility in Institute of Advanced Energy, Kyoto University. Irradiation temperature and dose were up to 1200 °C and 10 dpa. The SiC matrix was well crystallized and contained a small amount of secondary phases. The EDX analysis specified that the secondary phase was aluminum-rich. The SiC grains and the secondly phase exhibited enough microstructural and dimensional stability after the Si-ion.