Abstract:The paper discussed the influence of the changing of cropping system from upland farming to rotation of rice and upland farming on the total contents,available contents and morphology of microelements in lime concretion fluvo-aquic soils studied by using the sequential extracting method. The total contents of microelements except molybdenum were remarkably decreased and the available contents of microelements except zinc were increased with the changing of cropping system from upland farming to rotation of rice and upland farming. The contents of residual, crystalline iron oxide bound and carbonate bound microelements were reduced and the contents of amorphous iron oxide bound and organically bound microelements were gradually increased and the changes of exchangeable microelements were similar to that of available microelement contents.