The primary objective of this study is to determine which treatment will be more effective to reduce left ventricular mass in hypertensive patients with left ventricular hypertrophy comparing aliskiren and eplerenone.

Inclusion Criteria:

Male or female ≧ 20 years of age Clinical diagnosis of hypertension Patients who are able to provide written informed consent

Exclusion Criteria:

1. History of congestive heart failure, myocardial infarction, or coronary revascularization in the recent 6 months.
2. Planned to taking percutaneous coronary intervention and coronary artery bypass graft
3. Severe hypertension (≧ 180/110 mmHg) or secondary hypertension or malignant hypertension.
4. History of stroke, cerebral hemorrhage, subarachnoid hemorrhage, transient ischemic attack in the recent 6 months
5. Severe valvular heart disease or atrial fibrillation
6. Congenital heart disease
7. Severe heart failure (NYHA functional class Ⅳ)
8. Current treatment with aliskiren or eplerenone or diuretics
9. Taking potassium preparation or potassium-sparing diuretic
10. Estimated GFR ≦ 30ml/min/1.73m２ at screening or current treatment with hemodialysis
11. Potassium > 5.0mEq/L at screening
12. Diabetes mellitus with microalbuminuria or albuminuria
13. Impairment of liver function (liver failure, liver cirrhosis)
14. Pregnant woman or possibly pregnant woman
15. History of malignant tumor include hematological neoplasm
16. Current treatment with itraconazole, cyclosporin, ritonavir or nelfinavir
17. Prior treatment with, hypersensitivity to, intolerance of or contra-indication to aliskiren and/or eplerenone
18. Current participation in another clinical trial
19. Serious non-cardiovascular disease severely limiting life expectancy
20. Contra-indication to MRI