Abstract: AIM: To evaluate the efficacy and safety of the combination of irbesartan and enalapril in treating renal damage in hypertensive patients. METHODS: A total of 110 patients with essential hypertension (EH) complicated with mild renal insufficiency were included in this study. Fifty cases were treated with irbesartan (150-300 mg/day), 26 cases were treated with enalapril (5-10 mg/day) and 34 cases were treated with a combination of irbesartan and enalapril for 12 weeks. Renal hemodynamics and structural variations and blood and urine microglobulin of β2-MG were determined before and after treatment by color Doppler ultrasonography and kit. RESULTS: After the combination treatment of irbesartan and enalapril, both systolic and diastolic pressure were significantly decreased (P<0.01). In groups A, B, and C, β2-MG in blood and urine were obviously decreased (P<0.01) and RI, PI and Vm were markedly decreased in left and right kidney after treatment. Thickness of renal arterial wall was significantly decreased and the renal arterial diameter was obviously increased (P<0.05). Compared with those in group C, blood and urine microglobulin of β2-MG and RI, PI and Vm were markedly decreased in left and right kidney after treatment. CONCLUSION: Irbesartan combined with enalapril was effective in lowering blood pressure, decreasing the concentration of β2-MG in blood and urine, decreasing renal arterial vessel resistance, increasing renal blood flow and improving renal vessel structure, thus improving renal function.