Kinetics and mechanisms of dechlorination of chlorinated organic pollutants induced by ionizing radiation were described in this article. The progress on the dechlorination of chlorophenols, polychlorinated biphenyl, trichloroethylene, and perchloroethylen involved in radiolysis was also reviewed. In oxidative condition, hydroxyl radical (·OH) would attack chlorophenol to form ·OH-adducts, which could be dechlorinated gradually. However, chlorophenol can be directly reduced by hydrated electron(e,-,aq,) to release Cl,﹣,. It was found that radiolytical degradation of polychlorinated biphenyls in organic solvent would release chlorine atoms gradually by chain reactions and the final products were Cl,﹣,and biphenyl. Trichloroethylene and tetrachloroethylene mainly reacted with ·OH with the final products of CO,2, HCOOH and HCl. As conclusion, the reductive dechlorination of chlorinated organic pollutants possesses advantages of high degradation efficiency, simple products and relatively low radiation dose compared with the oxidation methods.