Amorphous hydrogenated silicon carbide(a-SiC:H) films were prepared by the reactive sputtering method, which were irradiated by high energy (average value is 1.25 MeV) γ rays. The absorbed dose of five samples were 0, 2×104, 4×104, 6×104, and 8×104 Gy respectively. Resistivity, Raman scattering and infrared transimissing spectroscopy were used to investigate the effects of γ rays irradiation on the structure and properties of a-SiC:H films. It is found that the increase of absorbed doses results in light crystallization in a-SiC:H films and the decrease in resistivity (the level is 105 Ω·cm). The main reason may be that Si which comes from the breakdown of SiOSi bonds takes the place of C of CC bonds in the films, and brings out the increase of crystal SiC. The infrared