AIM: To investigate the protective mechanism of Danggui Buxue Decoction(Radix Astragali,Radix Angelieae Sinensis) on the kidney of diabetic rats. METHODS: The diabetic animal model was made by a single intraperitoneal injection of 60 mg/kg streptozotocin(STZ) and treated with Danggui Buxue Decoction(DBD) or Benazepril. Renal weight/body weight ratio, blood glucose and lipid, urinary albumin and β 2-microglobin were measured. The renal pathological lesions were also investigated. The expression of TGF-β 1 mRNA in renal cortex as well as Angiotensin Ⅱ(AngⅡ) concentration of plasma and kidney tissue were determined by In situ hybridization and radioimmunoassay after 4,8 weeks of treatment. RESULTS:DBD had equivalent effects with Benazepril in protecting renal function and alleviating pathologic lesions. By means of inhibiting the expression of of TGF-β 1 mRNA. DBD had no effect on renal and plasmaAngⅡ. CONCLUSION:Danggui Buxue Decoction may alleviate kidney lesion and slow down the progression of DN by decreasing the renal expression of TGF-β 1 mRNA.