Based on the data of the species abundance, biomass,diversity index of Copepoda and regression analysis between its biomass and factors of the water quality were studied al stations (from I to IV) of West Lake Hangzhou,a shallow eutrophic lake after dredging treatment. During the survey in 2003,9 species of Copepoda (3 Cal-anoida and 6 Cyclopoida) were identified from the quantitative samples. The density of Copepoda community increased after the drawing water current, but diversity index decreased. The abundance of Copepoda was much higher in Summer-Autumn than that in Winter-Spring season. Sinocaianus dorrii adults was more abundant al Station I with relatively lower trophic status. (TLI =55.3),decreased along drawing water current, and Caianoida copep-odids density increased following the water current, while Thermocyclops dybowskii adults was more abundant at Stations II-IV with relatively higher trophic status (TLI =62.7-63.5),Harpacticoida disappeared after d reding treatment. The effect of dreding treatment on Caianoida community heterogeneity of distribution was much stronger than that on Cyclopoida community. The biomass of Copepoda was positively correlative with Chlorophyll-a, CODMn and total phosphorus, while negatively with water transparency at Stations Ⅱ-Ⅲ