OBJECTIVE:To prospectively investigate the effects of enalapril in decreasing ACE activity,renal function protection in diabetic nephropathy(DN)patients and prevention of deterioration from DN METHODS:62 DN patients were divided into two groups,31 in each group,the sex,age,disease duration and condition were comparable In treatment group,patients received enalapril 10mg/d in addition to routine anti-hyperglycemic and anti-hypertensive agents,in control group,patients had only routine treatment The observation lasted 18～36 months(mean 26 months) The BP,blood sugar and renal functions were compared between two groups before and after treatment RESULTS:In treatment group,blood sugar,BP and renal functions were significantly improved after treatment of enalapril(P0 05) CONCLUSION:Enalapril can lower ACE activity and protect the renal function,these effects do not depend on it’s anti-hypertension result