Dichlorobenzenes are a kind of organic contaminations which are usually difficult to be decomposed by normal methods. Decomposition of O-

M-

P-dichlorobenzenes by electron beam (1 mA

1.5 MeV) irradiation was studied in this paper. The irradiation doses of electron beam are 35 kGy

70 kGy

105 kGy

140 kGy

210 kGy

respectively. The results show that dichlorobenzenes can be decomposed efficiently with electron beam

the needed doses are 38 kGy

35 kGy

46 kGy

respectively

for O-

M-

P-dichlorobenzene with a degrading rate of 50%. The mass concentration of chlorine ion increased during irradiation and pH of irradiated solution was at the range of 2—3. Mechanism of dichlorobenzene decomposition is discussed in the paper according to the results of experiment.