Abstract: :Effects of drawing water and dredging on Rotifera community, including species composition, density, biomass and di2 versity index were studied at three sampling stations (Ⅰ2 Ⅲ) of the West Lake, Hangzhou, a shallow eutrophic lake in 1990, 1995 and 2003.The first dominant species of rotifers was from Keratella cochelearis in 1980 before drawing Qiantang River, be2 came Anuraeopsis fissa in 1990 and Trichocerca pusilla in 1995 after drawing water, Polyarthra trigla rose the first dominant species of rotifers in the West Lake, Hangzhou in 2003 after dredging.At different sampling stations, dominant species of rotifers changed, abundance decreased remarkably and had a strong relationship between rotifers biomass and Chlorophyll2a content (r = 0.7080, p < 0.01) at Station Ⅰ (import water region) after drawing water.Dominant species of rotifers changed, abundance in2 creased slowly and had a strong relationship between rotifers biomass and CODMn (r = 0.5440, p < 0.25) at Station Ⅲ (discharge water region) after dredging.There are significant positive correlation coefficients of each sampling station rotifers biomass and the water body TLI.Rotifers abundance rose sharply and diversity index continual declined at Station Ⅰand Station Ⅱwith drawing water quantity which into the lake decreased sharply, dredging engineering and eutrophication advance of the West Lake, Hangzhou, however, rotifers abundance increased slowly at Station Ⅲ.This indicated that eutrophication advance were faster at Station Ⅰand Station Ⅱthan that at Station Ⅲ