Abstract: The trichloroethylene in water was treated by Fenton reagent oxidation under microwave radiation. The effect of treating condition, including the treatment time, the weight and molar ratio of Fenton reagent, the initial concentration and pH of trichloroethylene, power of microwave radiation and pressure on the rate of dechlorination was studied by single factor method. It is obvious that the rate of dechlorination is related to treating conditions. The rate of dechlorination increases with the treatment time, power of microwave radiation and pressure, and decreases with the initial concentration of trichloroethylene. The weight and ratio of Fenton reagent and pH have the optimum conditions. In the optimum conditions : the molar ratio of Fenton reagent is 60, the weigh of Fenton reagent is 10%, the treatment time is 12 min, power of microwave radiation is 750W,the rate of dechlorination of trichloroethylene can reach up to 87.08%.