This paper deals with the effects of chlorobenzene (CB), 1, 2, 3-trichlorobenzene(1,2, 3-TCB) and hexachlorobenzene (HCB) on aquatic community structure (and function) in simulation 4-cell stabilization pond systems. The purification of three chlorobenzenes in systems are also discussed. The results show that the specific diversity and densities of Bacterium,Micrococcus and Saccharomyces species of microorganisms were not affected while the specific diversity, density and chlorophyll a synthesis of the alga...