A Valsartan 80 Mg-Referenced, Therapeutic Exploratory Clinical Study to Evaluate the Antihypertensive Efficacy of Fimasartan 30 mg During 24 Hours in Patients With Mild to Moderate Essential Hypertension

Inclusion Criteria: 1. Subjects aged 20 to 70 years 2. Essential hypertension subjects who are measured more 135/85 mmHg of average Diastolic Blood pressure (DBP) and Systolic Blood pressure (SBP) measured by ABP monitor at baseline visit(day 0) 3. Subjects who agreed to participate in this study and submitted the written informed consent 4. Subjects who considered to understand this study, be cooperative, and able to be followed-up whole of the study period Exclusion Criteria: 1. Severe hypertension patients; more 180 mmHg of mean sitting SBP and/or more 110 mmHg of mean sitting DBP measured as an office Blood pressure (BP), before Randomization (Screening visit, Placebo run-in visit, Pre-Baseline visit, Baseline visit) 2. Patients with difference of office BP at selected one arm over DBP 10 mmHg and/or SBP 20 mmHg at screening visit 3. Patients with secondary hypertension 4. Patients with symptomatic orthostatic hypotension 5. Patients with severe insulin dependent or uncontrolled diabetes mellitus (HbA1c \> 9%, increased regimen of oral hypoglycemic agent, using insulin at baseline visit) 6. Patients with severe heart disease, ischemic heart disease within 6 months, peripheral vascular disease, Percutaneous Transluminal Coronary Angiography (PTCA), Coronary Artery Bypass Graft (CABG) 7. Patients with significant ventricular tachycardia, atrial fibrillation, atrial flutter or other significant arrhythmia 8. Patients with hypertrophic obstructive cardiomyopathy, severe obstructive coronary artery disease, aortic stenosis, hemodynamically significant aortic valve or mitral valve disease 9. Patients with severe cerebrovascular disease within 6 months 10. Patients with known severe or malignancy retinopathy within 6 months 11. Patients with wasting disease, autoimmune disease, connective tissue disease 12. Patients with significant investigations - abnormal renal function (Creatinine more 1.5 times than upper limit of normal), abnormal liver function (Aspartate Transaminase(AST), Alanine Transaminase(ALT) more 2 times than upper normal) 13. Patients with surgical or medical disease which is able to be affect to absorption, distribution, metabolism, excretion 14. Patients with hereditary disorders of galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption 15. Patients with significant investigations - Hypokalemia(Less than 3.5mmol/L), Hyperkalemia(exceeded 5.5mmol/L) 16. Patients with depletion of body fluid or sodium ion not able to correct 17. Patients with suspected or history of drug or alcohol abuse within the past two years 18. Childbearing, breast-feeding women and female who plan to become pregnancy or have a possibility of pregnancy but don't prevent conception with acknowledged methods 19. Patients with any chronic inflammation disease needed to chronic inflammation therapy 20. Patients with hepatitis type B or type C and carriers 21. Patients with laboratory test results indicating clinically significant abnormal results 22. Patients receiving medication that can affect blood pressure 23. Patients with history of allergic reaction to any angiotensin II antagonist 24. Patients with the medical histories of malignant tumor within 5years, except local basal cell carcinoma of the skin 25. Patients who took investigational drug within 12 weeks from screening visit or is going on the progress of other clinical trial 26. Subject who are judged unsuitable to participate in this study by investigator