Abstract: Chlorinated benzens in the environment could not be readily degraded anaerobi-cally. The residual amount of this compound in the environment chiefly depended on the rate of bio-degradation. In this paper, an experiment has been conducted on the bio-degradation of that compound for the flooded soil under anaerobic condition and moist soil under aerobic condition collected from the irrigated area of Datong river in Changzhou city of Jiangsu province. Based on these experiments, the cause of high content of chlorinated benzen compounds has been investigated and its coun-termeasures prorosed.