Abstract: A series of experiments on degradation of phenol were performed by ⁶⁰Co γ-ray irradiation with a dose rate of 0.72 kGy/h. The effects of phenol concentration, ammonia concentration, absorbed dose, initial pH value and free radical scavenger on irradiation degradation efficiency were studied by analyzing the change of phenol concentration, chemical oxygen demand(COD) and pH value under different absorbed doses. The results indicate that the degradation of phenol with high-strength ammonium is effective by ⁶⁰Co γ-ray irradiation, and phenol and COD removal rate increase with the absorbed dose. The radiation degradation of phenol is in conformity with the first order kinetics equation. Under the same absorbed dose, the higher the initial concentration of phenol is, the lower phenol removal rate is. Ammonia concentration has no effect on removing phenol from aqueous solution by gamma radiation. Ammonia concentration has no obvious change before and after irradiation. And the weakly acidic condition is more helpful to the removal of phenol. The radiation degradation mechanism of phenol is main •OH oxidation.