• The primary endpoint is the reduction from reference baseline in mean seated diastolic blood pressure (DBP) at trough (24 hour post dosing) after 8 weeks of the double blind treatment. [ Time Frame: 8 Weeks ]
  

• Reduction in seated systolic blood pressure (SBP) Control rate in SBP/DBP Response rate in SBP/DBP Normalisation [ Time Frame: 8 Weeks ]
  

Drug: telmisartan+amlodipine
T40mg/A5mg/day
Drug: amlodipine
A5mg/day

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 DBP > 114 mmHg and/or mean seated 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 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