The effects of root system of corn, bean and wheat on the fractionation of copper, lead, cadmium and zinc in rhizosphere in farmland soil irrigated with wastewater were studied. It was revealed that the levels of exchangeable copper increased significantly in rhizosphere soil under influence of wheat, corn, or bean. For bean, metals bound to carbonate and Fe-Mn oxide decreased. No change in level of organic bound metals was detected. It is believed that the dominant transformation processes occurred in the rhizosphere were the transformation of carbonate and Fe-Mn bound metal to exchangeable fraction. The effect of root system of bean was much more notable than that of wheat and corn.