Abstract: By using niche analysis for 14 dominant species at the six station in Shuimo River,Urumqi, the reationships between community structure and water pollution were discussed.The niche ordinahon from the overlap matrix resulted in a r-k continuum of successional gradients, and based on it the commnity dendrogram was also made by cluster analysis.The commnity was separated into four guilds and one fringe species. The author described the polluted characteristies of each guilds of benthic animals and ecological strategy of successional species.