【Abstract】 Objective To study the expression of angiopoietins(Ang), Tie-2 and vascular endothelial growth factor(VEGF) in the renal tissue of diabetic rats and the effect of Losartan on their expression. Methods SD rats were randomized into normal control group (group A), diabetes group (group B) and diabetes treated with Losartan (group C). Renal expression of VEGF, Ang-1, Ang-2 and their receptor Tie-2, were assessed using real-time reverse transcription 杙olymerase chain reaction and immunohistochemistry. Results The expression of VEGF and Ang-2 increased significantly in the renal cortex of group B compared with that in group A (P＜0.05). Ang-2, Tie-2 and VEGF expression of group C decreased significantly compared with group B (P＜0.05). Ang-2 expression correlated positively with mean glomerular volume and urine protein/creatinine ratio (P＜0.05). Conclusion Ang/Tie-2 may play an important role in the development of early diabetic nephropathy. Losartan may exert an renal protection on diabetic nephropathy, possibly partly through the changes of these vascular growth factors expression.