Objective To study the effect of La on antioxidase activity and ROS content in crucian liver stressed by cadmium.Methods The crucian were randomly divided into the control group, the 0.5 mg/L Cd2+exposed group and the low(0.5 mg/L Cd2++0.25 mg/L La3+),moderate(0.5 mg/L Cd2++0.5 mg/L La3+),high(0.5 mg/L Cd2++1 mg/L La3+)La3+ intervention groups.The activity of SOD,CAT and ROS activity in crucian liver was detected on the first day, the third day and the fifth day.Results The CAT and SOD activity in the Cd2+exposed group was higher than that in the control(P