Abstract: In this paper,the functions of macrophyte in constructed wetland wastewater treatment system were approached,with the major environmental factors affecting macrophyte growth analyzed.The results showed that macrophyte during its growth period had different nitrogen and phosphorous assimilation,and the removal of nitrogen and phosphorous through harvesting in autumn or winter was rather low.It was considered that macrophyte should not be harvested but used as thermo-keeping material in cold winter.Some ideas of adopting integrated treating technologies were proposed to improve the removal efficiency of nitrogen and phosphorous in constructed wetlands.

Key words: Eutrophication, Planted float system, N and P, Nitrification and denitrification, Removal, N₂O