Abstract:Recent studies on decontamination of heavy metals by wetland plants and soils are reviewed. Wetland plays an important role in removal of heavy metal contamination, which is under intensive study. Most researches have been focused on the function and the processes of wetlands. The functional compositions of wetland include plants, microbes, water and soil, among which plants play a key role in the removal of heavy metals. Phytoremediationis contributed mainly from three parts: phytoextraction, phytovolatilization and phytostabilization．Plants have great effects in heavy metal removal via modulating pH,transporting O2 stimulating microbes, erc．The detaining of heavy metals in soils is related to soil particle size and other traits, such as the basic elements of soil,organic material, pH, etc．It is proved that the organic material content has the effect of concentrating heavy metals via cation exchange， surface adsorption，chelation with solid organic material，etc．But it is also found that the stability of the organic complexation，chelating with acid，is highly pH dependent．Wetland，therefre，is a system in which most of the factors will work together and affect each other．The function of wetland，especially those with rich biodiversity, is extremely complex．In artificial wetland construction and research，more attention should be paid to the cooperation of various factors than the function ofindividual one．
