OBJECTIVE：To stu dy the improvement effect s of Dantaojin （Salvia miltiorrhiza ，Persicae Semen ，Curcumae Radix）extract on oxidative stress of liver and kidney in chronic lead poisoning model mice. METHODS ：Totally 72 mice were randomly divided into normal control group ，model group ，positive control group （dimercaptosuccinate，70 mg/kg），Dantaojin extract low-dose ，medium-dose and high-dose groups （20，40，60 g/kg），with 12 mice in each group. Except for normal control group，other groups were given intraperitoneal injection of lead acetate solution 20 mg/kg（every other day ，consecutive 20 days） to establish chronic lead poisoning model. After modeling ，administration groups were given relevant medicine intragastrically ， normal control group and model group were given constant volume of water intragastrically ，once a day ，for consecutive 20 days. After last medication ，body weight of mice was weighed ，and organ coefficients （kidney and liver ）were calculated. Serum levels of ALT ，AST，BUN and Scr were determined by automatic biochemical detector. HE staining was used to observe histopathological features of liver and kidney. ELISA method was used to determine the levels of GSH-Px ，SDO and MDA in liver and renal tissue. RESULTS：Compared with normal control group ，body weight （except for high-dose group ），the levels of SOD （except for high-dose group ）and GSH-Px were all decreased significantly in model group and Dantaojin extract groups ，while the renal coefficients（except for high-dose group ），liver coefficients （except for low-dose ，medium-dose and high-dose group ），the levels of BUN （except for high-dose group ），Scr，AST（except for high-dose group ），ALT and MDA were increased significantly （P＜ 0.05 or P＜0.01）. The epithelial cells of glomerulus and renal tubules were atrophied ，the arrang ement of hepatocytes was loose and some cells were necrotic. Compared with model group ，body weight ，the levels of SOD and GSH-Px were increased significantly in positive control group and Dantaojin extract groups，while the renal and liver coefficients ，the levels of BUN，Scr，AST，ALT and M DA were decreased significantly（P＜0.05 or P＜0.01）. Histopathological fea tures of liver and renal tissue were improved significantly in Dantaojin extract medium-dose and high-dose groups. CONCLUSIONS ：Dantaojin extract could improve oxidant stress injury in liver and renal tissue，the mechanism of which may be associated with eliminating reactive oxygen radicals ，inhibiting lipid peroxidation and enhancing antioxidant defense ability.