Abstract: Objective To investigate the influence of chronic cadmium exposure via drinking water on antioxidant function of testis and blood in rats.Methods Thirty male Sprague-Dawley rats(sexual maturity) were randomly divided into 5 groups and supplied with drinking water containing different concentration(0,25,50,100,and 200 mg/L) of cadmium chloride(Cd) continuously for 56 days,respectively.At the end of the treatment,the samples of abdominal aortic blood and testis of the rats were collected for the detections of activity of glutathione peroxidase(GSH-Px),superoxide dismutase(SOD),and malondialdehyde(MDA).Results Compared with the control group,the GSH-Px activity(7.94±2.25 μmol/min·gprot) declined significantly(P <0.05) and the MDA content(5.84±0.61 nmol/mgpr) increased significantly(P <0.01) in testicular tissue for the rats in 200 mg/L Cd group.Compared with the control group,the whole blood GSH-Px activity(32.99±4.45 μmol/min·gprot),erythrocyte SOD activity(8574.79±887.65 NU/gHb),and plasma SOD activity(9.94±1.38 NU/mgprot) declined significantly(P <0.05),but plasma MDA content(0.26±0.03 nmol/mgprot) increased significantly(P <0.05) for the rats in 200 mg/L Cd group. Conclusion Chronic cadmium exposure via drinking water can cause antioxidant function damage in rats.