To investigate the protective effect of Yiqi Huoxue decoction on the kidney in diabetic goto-Kaizaki (GK) rats. Eight Wistar rats were used as normal control group. According to body weight and blood glucose, 16 GK rats were randomly divided into model control group and Yiqi Huoxue group, with 8 rats in each group. Drugs were administrated for 6 weeks. The rats were weighed and fasting blood glucose (FBG) were measured weekly; the glycosylated hemoglobin (HbALc) and 24 h metabolic rate were measured at the end of third and sixth weeks, at the same time, urine was collected to measure urinary glucose (U-GLU), urinary creatinine (U-CREA) and total proteinuria (U-TP) by biochemical method and calculate 24 h protein excretion rate (UAER). At the end of treatment, rats were sacrificed in anesthesia, and creatinin (CREA), uric acid (UA) and cholesterol (CHOL) were detected by biochemical method and glutathione peroxidase (GSH-Px) was detected by manual method with the blood drawn from heart. Both kidneys were taken and weighed to calculate the renal hypertrophy index. The kidneys were placed into neutral formalin and observed under light microscope for pathological change after Periodic Acid-Schiff (PAS) staining. The results showed that as compared with the normal control group, FBG, HbALc, 24 h Metabolic rate, U-GLU, UAER, serum CREA, UA and CHOL levels, as well as renal hypertrophy index were significantly increased (P<0.05) in the model group, while the body weight growth rate, serum GSH-Px level were significantly reduced(P<0.05); in addition, renal glomerular injury and structural changes were observed in the model group. As compared with the model group, serum GSH-Px level was significantly increased (P<0.05) in the Yiqi Huoxue group, While FBG, HbALc, 24 h Metabolic rate, U-GLU, UAER, serum CREA, UA and CHOL levels, as well as renal hypertrophy index were significantly reduced (P<0.05); meanwhile, renal glomerular injury and structural changes were improved in the Yiqi Huoxue group. The results showed that Yiqi Huoxue decoction can significantly increase serum GSH-Px level, reduce FBG, HbALc, 24 h metabolic rate, U-GLU, UAER, serum CREA, UA and CHOL levels, as well as renal hypertrophy index, and improve renal pathology in diabetic GK rats.