Abstract: To investigate plant rhizospheric effects on biodegradation of chlorobenzene compounds in constructed wetlands, Phragmites australis and Typha angustifolia, two typical wetland plants, were selected and planted in a simulated outdoor constructed wetland mesocosm to explore changes in population of soil microbe and activity of soil enzyme in the rhizosphere of the plants under stress of hexachlorobenzene. Results show that both P. australis and T. angustifolia significantly affected soil microbe (bacteria, fungi and actinomycetes) in population and soil enzymesdehydrogenase (DEH), catalase (CAT) and polyphenol oxidase (PPO), in activity in the rhizosphere, which were all higher than in the non-rhizosphere soils, and the rhizosphere effects of T. angustifolia were higher than those of P. australis (P<0.05). Population of the soil microbe and activities of the soil enzymes were found negatively related to concentration of HCB in the rhizospheres of P. australis and T. angustifolia,and particularly to the activities of DEH and PPO in the rhizospheres of T. angustifolia(P<0.01). The rhizospheric effects of the two plants increased with the increase in microbial population and enzyme activity in the rhizospheres of the plants, which in turn helps remove HCB in the wetland ecosystem.