A Multicenter, Phase 3 Study to Evaluate the Antihypertensive Efficacy and Safety of Fimasartan(BR-A-657∙K) 30mg Compared to Placebo in Patients With Mild to Moderate Essential Hypertension

Inclusion Criteria: 1. Subjects who agreed to participate in this clinical trial and submitted the written informed consent 2. Subjects aged 20 to 75 years 3. Essential hypertension patients who are measured more 90mmHg, less than 110mmHg of sitting diastolic blood pressure(SiDBP) at baseline(Day 0) 4. Subject who considered to understand this clinical trial, be cooperative,and able to be followed-up whole of the clinical trial period Exclusion Criteria: 1. Severe hypertension patients: more 110mmHg of mean SiDBP and/or more 185mmHg of mean Sitting systolic blood pressure(SiSBP) 2. Patients with orthostatic hypotension who has sign and symptom 3. Patients with secondary hypertension 4. Patients who are measured the difference of mean blood pressure of one arm under SiDBP 10mmHg or SiSBP 20mmHg at screening and baseline visit 5. Patients who cannot stop administration of hypertension medication through the clinical trial period, and can take any other hypertension medication except investigational drugs 6. Patients with significant investigations-abnormal renal function (Creatinine more 1.5 times than upper limit of normal), abnormal liver function(AST, ALT more 2 times than upper limit of normal), severe fatty liver disease needed medication 7. Patients with clinically significant investigations in laboratory test of screening visit 8. Patients with surgical and medical disease that is able to be affect to absorption, distribution, metabolism and excretion 9. Patients with severe insulin dependent or uncontrolled diabetes mellitus (HbA1c\>9, regimen change of oral hypoglycemic agent, using insulin) 10. Patients with severe heart disease, ischemic heart disease within 6 months, peripheral vascular disease, Percutaneous transluminal coronary angiography(PTCA), Coronary artery bypass graft(CABG) 11. Patients with significant ventricular tachycardia, atrial fibrillation, atrial flutter or other significant arrhythmia 12. Patients with hypertrophic obstructive cardiomyopathy, severe obstructive coronary artery disease, aortic stenosis, hemodynamically significant aortic valve or mitral valve disease 13. Patients with severe cerebrovascular disease 14. Patients with wasting disease, autoimmune disease, connective tissue disease at present and/or previous 15. Patients with known severe or malignancy retinopathy 16. Patients with hepatitis B or C or HIV positive reaction 17. Patients with the medical histories of malignant tumor within 5 years,except local basal cell carcinoma of the skin 18. Patients who have a story or evidence of alcohol or drug abuse within 2 years 19. Patients with history of allergic reaction to any angiotensin II antagonist 20. Patients with any chronic inflammation disease needed to chronic inflammation therapy 21. Childbearing and breast-feeding women 22. Female who plan to become pregnancy or have a possibility of pregnancy but don't prevent conception with acknowledged methods 23. Patients who took medicine within 12 weeks from screening visit or is going on the progress of other clinical trial 24. Patients with significant investigations-Hypokalemia(Less than 3.5 mmol/L), Hyperkalemia(exceeded 5.5 mmol/L) 25. Patients with sodium ion or body fluid is deplated and not able to correct 26. Subject who are judged unsuitable to participate in this clinical trial by investigator