【Abstract】 Objective To observe the calcification and the expression of BMP2，Runx2 in renal artery as well as renal arteriole in type 2 diabetic nephropathy rats. Methods 24 male rats were randomly divided into control group (N group) and diabetic nephropathy group (DN group). Type 2 diabetic nephropathy model was established by high sugar and fat diet and streptozotocin (STZ) injection. Calcium depositing in the renal artery as well as renal arteriole were observed by von Kossa staining. The protein expression of BMP2 and Runx2 were detected with immunohistochemistry. Results Contents of blood glucose, blood urea nitrogen( BUN ), cystatin C (Cys C), Serum creatinine (Scr) and 24 h urinary protein (24 h Upro) of group DN at all time point were much higher than those of group N (P＜005). Black granules were found deposited in the renal artery of DN rats in 12 and 16 weeks and the black calcium salt was gradually increased with the time passing. No calcium salt was found in group N. However, no calcium Salt was found in group N and group DN in the renal arteriole. The protein expression of BMP2 and Runx2 in group DN rats were significantly higher than that of N group in renal artery. The expression of BMP2 and Runx2 in the renal arteriole was little, which had no statistical significance from that of the normal group. Conclusion The renal artery calcification may appear in the early stages of type 2 diabetic nephropathy rats model, while there is no obvious calcification in the renal arteriole. It indicates that vascular calcification is more occurred in large blood vessels and less prone to occur in arteriole in the viscera.