The phytoplankton samples were seasonally collected from 11 suburb rivers for leisure situated in green belt around City of Shanghai in 2017. The effects of submerged macrophyte on the structural characteristics of phytoplankton community and its relationship with environmental factors were analyzed. A total of 143 species belonging to 8 phyla and 83 genera were identified and the density and biomass averaged (17.10±0.64)×10⁶ ind/L and (3.28±0.58) mg/L, with the maximam density for blue-green algae (Cyanophyta) and biomass for diatom (Bacillariophyta). The species composition of phytoplankton community of rivers with submerged macrophyte (WSM) significantly differed from those without submerged macrophyte (NWSM). The two clusters were seperated by indicator species of Merismopedia tenuissima, Oscillatoria sp., and Chroomonas acuta, with characteristic species of M. tenuissima, Oscillatoria sp. for the cluster NWSM and C. acuta for the cluster WSM. The density (P<0.001), biomass (P<0.01) and species richness index (R, P<0.001) for the cluster of WSM were significantly lower than those for the cluster of NWSM. The two clusters significantly differed in Shannon's species diversity index (H'), but did not in evenness index (J), with season×cluster interactions for those two indices. The density of phytoplankton community was significantly correlated with five-day biochemical oxygen demand (BOD₅), chemical oxygen demand (COD_Mn), ammonia nitrogen (NH₃-N), total nitrogen (TN) and total phosphorus (TP), and its biomass conspicuously did with BOD₅ and TN. Redundancy analysis (RDA) showed that BOD₅ and the presence of submerged macrophyte were the key environmental factors responsible for spatial distribution of phytoplankton species. The higher density of the most main species included in RDA, such as M. tenuissima, Oscillatoria sp, Pseudanabaena sp., Chlorella vulgaris and Melosira sp.，occurred in rivers with the higher concentration of BOD₅ and absence of submerged macrophyte, while there was a trend of the higher density of C. acuta at rivers with the presence of submerged macrophyte. Based on the comprehensive trophic level index (TLI), indictor species method, R, and H',the rivers were considered to be moderately polluted and eutrophicated. The R and H' are more suitable to assess the water quality of the rivers without and with submerged macrophyte, respectively.