Abstract: An investigation was made on the water quality and plant community in 17 urban wetlands in east suburb of Nanjing City, and the spatial heterogeneity of the water quality was analyzed at ecosystem scale, catchment scale, and functional landscape scale. Wetland type and the characteristics of plant community were the main factors affecting the water quality at ecosystem scale. Primitive wetland had the best water quality, followed by reconstructed wetland, and secondary wetland. The higher plant coverage the wetland had, the better the water quality was. Land use type was the main factor affecting the water quality at catchment scale. Constructive land had greater effects on water nutrients content, while woodland mainly affected water dissolved oxygen. Human activity was the main factor affecting the water quality at functional landscape scale, and the effects differed with different water quality indices.

Key words: urban wetland, multi-scale, water quality, Nanjing City, branch biomass, foliage biomass, linear mixed effects model,  , Cunninghamia lanceolata.