Abstract:The water quality of 8 sampling points in the first phase of Haizhu National Wetland Park were monitored. The results showed that the concentration of total phosphorus, total nithogen, NH4+-N and chemical oxygen demand were lower in the communities of Thalia dealbata + Canna indica-Vallisneria natans, Canna indica + Acorus calamus-Vallisneria natans, Thalia dealbata + Cyperus alternifolius-Vallisneria natans, and Arundo donax var. versicolor + Hydrocotyle vulgaris-Vallisneria natans, which showed much better water quality. It was speculated the purification effect of Vallisneria natans on water quality was obvious.