Abstract: Objective To study the organic pollution and genotoxicity of the pollutants in aquatic environment of Qiantangjiang River.Methods The activity of ethoxyresorufin-O-deethylase(EROD)activity in liver of wild crucian and genotoxicity of extracts of water samples from 7 monitoring sites of Qiantangjiang River were detected.Results EROD activities in liver of wild crucian from Zhangtan,Jiangjunyan,Fuyang and Wenyan(23.51±4.17,16.79±7.39,18.74±5.16,18.65±8.86 nmol/gpm·min)were significantly higher than that of Jiekou (7.84±2.42 nm of/g pro·min)，and no difference was observed between the other sites and Jiekou.Three dose groups(0.25,0.50,1.00L/dishwater sample extracts) were used in Ames test Reversional mutation mte of TA98 colony exposed to extracts from Zhangtan was 2.21,3.39,6.95 without S9,and 2.70,4.07,6.23 with S9,respectively.The revesional mutation of TA 100 colony was 2.55,2.81,5.36 without S9,and 1.73,2.86,4.14 with S9,respectively Reversional mutation rate of TA98 colony exposed to 1.00L/dish extracts from Jiangjunyan with S9 was 2.22,and there was a dose-response relationship in reversional colony count Ames tests of the other extracts were negative.Conclusion A quatic environment of Qiantangjiang River may be polluted by organics,and the extracts of water samples present gentoxicity based on Ames rest.