Etrazine is one of the most widely used herbicides in China and the world. Acute and chronic toxicity tests werc carried out to assess the possible toxicity effect of atrazine on crucian carp （Carassius auratus）. Results showed that 96 h LC,. of atrazine to Carassius auratus was 105.94 mg. L-1. The enzyme activities of superoxide dismutase （SOD）, catalase （CAT） and glutathione-S-transferases （GST） in kidney of Carassius auratus were all influenced by atraizine, and CAT was more sensitive to atrazine compared with SOD and GST. Atrazine residues in kidney of Carassius aura/us reached the stable state at day 19, and the bioaccumulation factors （BAF） of atrazine in kidney of Carassius auratus treated with 1.0 mg. L-1 and 10.0 mg. L-1 atrazine were 8.3 and 4.4, respectively. The research demonstrated that atrazine could cause oxidative stress to fish kidney, but atrazine was not easy to accumulate in Carassius auratus kidney, and the antioxidant enzymes could be used as biomarker to the early detection of pollution.