Abstract: By applying GPS orientation, field specimen collection and Braun-Blanquet Cover Abundance Scale Method, the plant species composition, community type, species diversity index, ecological dominance index, and community evenness index in two wetlands of Nanjing suburb were studied, and the results showed that there were 104 species of vascular plant, belonging to 93 genera and 45 families, among which, Ceratopteris thalictroides, Glycine soja, Trapa incisa and Nelumbo nucifera were the grade Ⅱ rare and endangered plants protected by national law. Geographic element analysis of both genera and species demonstrated that temperate elements took dominant position, and tropic elements occupied definite proportion. The vegetations were classified into 3 vegetation types, 3 sub-vegetation types and 16 formations. The species diversity in the natural wetlands of Nanjing suburb was relatively low, being higher in Qilihe wetland than in that at the mouth of Chuhe. Countermeasures were put forward for the biodiversity protection of vascular plant communities in the natural wetlands of Nanjing suburb, based on the analysis of the characters of the plant communities and the existing problems.

Key words: Grey model, Nutrients, Chlorophyll a, Phytoplankton, Red tide, Daya bay