Antihypertensive Efficacy and Tolerability and Determine the Adequate Antihypertensive Dosage of Fimasartan in Mild to Moderate Essential Hypertension Patients

Inclusion Criteria: * Mild to moderate essential hypertension : sitting diastolic blood pressure measured at Screening and Baseline(Day1) are 95\~114 mmHg inclusive and the difference between sitting diastolic blood pressures measured at Day -14 and Baseline(Day1) is under 7mmHg. * Subjects who agree to participate in this sudy and give written informed consent * Subjects considered to understand the study, be cooperative, and able to be followed-up until the end of the study Exclusion Criteria: * The sitting DBP is less than 94mmHg or more than 115mmHg or severe hypertensive patient with sitting systolic blood pressure over 200mmHg * Patients with secondary hypertension * Patients with severe renal(Creatinine more 1.5 times than upper limit of normal), gastrointestinal, hematological or hepatic(AST, ALT more 2 twice more than upper limit of normal)disease etc. which might affect absorption, disposition, metabolism or excretion of the drug * Patients with postural hypotension * Patients with sever insulin dependent diabetes mellitus or uncontrolled diabetes mellitus(HbA1c\>9%, regimen change of oral hypoglycemic agents within 3 months, treated insulin before screening) * Patients with a history of myocardial infarction, severe coronary artery disease or clinically significant heart failure or valvular defect in last 6 months * Patients with consumptive disease, autoimmune disease, connective tissue disease * Patients with a history of type B or C hepatitis * Patients with HIV or hepatitis * Patients with clinically significant laboratory abnormality * Patients receiving any drugs known to affect blood pressure or medical treatments that can influence the blood pressure * Patients with allergy or contraindication to any angiotensin II receptor antagonists * Female of childbearing potential who does not undergo hysterectomy or is not post-menopausal * Patients judged to have a history of alcohol or drug abuse by the investigator * Patients with average weight \> +35% or \<-15% in Modified Metropolitan Life Insurance table * Patients participated other clinical trial 3 months before Screening * Patients judged to be inappropriate for this study by the investigator with other reasons