Inclusion Criteria:

1. Essential hypertensive patients satisfying all of the following criteria;
2. Male or Female
3. Age > 20 years
4. Outpatient
5. Patients who are able to stop current anti-hypertensive therapy at Visit 1 if taking any anti-hypertensive medications
6. Patients with an ability to provide written informed consent in accordance with the related laws and guidelines such as Good Clinical Practice (GCP) and the Pharmaceutical Affairs Law.

Exclusion Criteria:

1. Taking four or more anti-hypertensive medications
2. Secondary hypertension
3. Mean seated diastolic blood pressure (DBP) > 114 mmHg and/or mean seated systolic blood pressure (SBP) > 200 mmHg at Visit 1, 2, 3, or 4, or mean seated DBP < 90 mmHg at Visit 3.
4. Sustained ventricular tachycardia or other clinically relevant cardiac arrhythmias
5. Congestive heart failure patients with the New York Heart Association (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 angiotensin II receptor blockers (ARBs) or angiotensin converting enzyme (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 nonsteroidal anti-inflammatory drugs (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:

    • Pregnant or possibly pregnant (1)
    • Nursing (2)
    • Desire to become pregnant during study period (3)
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