 It is reported that the risk of a cardiovascular event occurring is 1.78 times higher in patients with diabetic nephropathy DN than in patients without DN. It is also reported that angiotensin II receptor blockade ARB prevents the progression of DN in diabetic patients with early phase nephropathy beyond its blood pressure lowering effect. The guidelines by the Japanese Society of Hypertension 2004 recommended that it was necessary to control blood pressure BP below 13080 mmHg in all diabetic patients. This has become the universal target BP for the prevention of cardiovascular events in hypertensive patients. On the study of intensive medical treatment including angiotensin-converting enzyme inhibitor ACEI, it is reported that ACEI not only prevents the progression of DN in microalbuminuria but also decreases proteinuria 1 gday in the nephrotic syndrome. Therefore, ACEI is thought to be effective for DN. However, it is not clear whether or not intensive medical treatment including ACEI improves nephropathy with proteinuria 1 gday. 