Inclusion Criteria:

1. Essential hypertensive patients who satisfying non-responder criteria
2. Male or Female
3. Age 20 years or older
4. Outpatient

Exclusion Criteria:

1. Taking four or more anti-hypertensive medications
2. Secondary hypertension
3. Mean seated DBP > 114 mmHg and/or mean seated SBP > 200 mmHg during run-in, or less than 90 mmHg in DBP during T40 mg monotherapy
4. Sustained ventricular tachycardia or other clinically relevant cardiac arrhythmias
5. Congestive heart failure patients with NYHA functional class III-IV
6. History of myocardial infarction or cardiac surgery within last 6 months
7. History of coronary artery bypass graft or percutaneous coronary intervention (PCI) within last 3 months
8. History of unstable angina within last 3 months
9. Hypertrophic obstructive cardiomyopathy, aortic stenosis, hemodynamically relevant stenosis of aortic or mitral valve
10. History of stroke or transient ischemic attack within last 6 months
11. History of sudden exacerbation of renal function with ARBs or ACE inhibitors, or patients with post-renal transplant or post-nephrectomy
12. Experienced characteristic symptoms of angioedema during treatment with ARBs or ACE inhibitors
13. Known hypersensitivity to any component of the investigational drug, or a known hypersensitivity to dihydropyridine -derived drugs
14. Hepatic and/or renal dysfunction
15. Diagnosed biliary atresia or cholestasis
16. Hyperkalemia
17. Dehydration
18. Sodium deficiency
19. Chronic administration of high doses of acidic NSAIDs
20. Patients who cannot change to the restricted administration and dosage during study period
21. Pre-menopausal women who meet any one of the following 1) - 3):

1) Pregnant or possibly pregnant 2) Nursing 3) Desire to become pregnant during study period 22. Drug or alcohol dependency 23. Complication of malignant tumour or a disease requiring immunosuppressants 24. Compliance of < 80% or > 120% during the run-in period 25. Receiving any investigational therapy within 3 months 26. Judged to be inappropriate by the investigator or the sub-investigator