Abstract: Coal samples were activated using a γ-ray as an irradiation source. Electro spin resonance (ESR), gas chromatography (GC) and linear sweep voltammetry (LSV) were employed to investigate the effects of γ-rays radiation on the change of free radical and structure of coal. The results show that γ-rays irradiation could promote the cleavage of alkane chains and heteroatoms in coal, leading the generation of free radicals and gas with low molecular weight, such as hydrogen, methane and ethane. Radical concentration reaches the maximum at 40 kGy. The increase of free radical could improve the electro-reduction of coal. The current density is reached the maximum at 40 kGy.