Various guidelines recommended angiotensin converting enzyme (ACE) inhibitors or angiotensin Ⅱ receptor-1 blockers (ARBs) for hypertensive patients with diabetes on the basis of the cardiac- and reno-protective effects of these drugs. However, these recommendations could not be extrapolated to Japanese patients, because Japan has been known as a country with a low incidence of coronary artery disease and a high incidence of cerebrovascular disease. Furthermore, calcium channel blockers (CCBs) also were protective against renal function as well as ACE inhibitors in Japanese diabetic hypertensive patients. This study will test whether ARBs or CCBs are superior in treating Japanese diabetic hypertensive patients.