AIM: To investigate the effect of puerarin on expressions of MMP-2 and TIMP-2 in the kidney of diabetic rats. METHODS: Uninephrectomized male Wistar rats were used to induce diabetes by intraperitoneal injection of streptozocin (65 mg x kg(-1)). Puerarin was given daily by intraperitoneal injection from the third day of induction of diabetes for 16 weeks. Using in situ hybridization and immunohistochemistry to detect MMP-2, TIMP-2 mRNA expressions and MMP-2, TIMP-2, collagen IV and Laminin expressions in diabetic kidneys with image analysis system, Flow cytometry was used to detect the expressions of TGFbeta1, MMP-2 and TIMP-2. RESULTS: Compared with those in kidneys of control group, expressions of MMP-2 mRNA and proteins were lower, while the expressions of both TGFbeta1 and TIMP-2 were higher in the diabetic kidney (P < 0.05). The level of MMP-2 expression was advanced, while expression of TIMP-2 was reduced by puerarin treatment (P < 0.05). CONCLUSION: Puerarin showed some renal protective effect on diabetic nephropathy, partly through inhibition of excessive deposition of glomeruli extracellular matrix by up-regulating MMP-2 and down-regulating TIMP-2 expressions besides reducing the blood glucose.