Abstract: Experiments are designed to study the purification effects on eutrophic water bodies by using wetland aquatic plants. Eight wetland plant species（Thalia dealbata Fraser, Canna indica L., Iris tectorum Maxim., Hydrilla verticillata, Oenanthe javanica (Blume) DC, Monochoriapauciflora（Bl.）Kunth., Marsilea quadrifolia L., Myriophyllum verticillatum L.）were screened in Chaohu Tongyang wetland to compare the purification efficiency of wetland plant species on eutrophic water bodies. The results showed that the highest removal rate of CODCr was Thalia dealbata Fraser, the rate of removal reaches 81.33 percent in 30 d. Thalia dealbata Fraser, Canna indica L. and Oenanthe javanica (Blume) DC were better plants for NH3-N and TP removal. The rates of removal were 75.54%, 84.66%, 76.22% and 73.61%, 77.33%, 82.67% respectively. The removal rates of purging eutrophic water were above 50% for TP on eight plants. 

Key words: hydrophyte, eutrophication, purge