Fimasartan (BR-A-657-K), a selective blocker of AT1 receptor subtype, showed the rapid and potent antihypertensive effect in many hypertensive models. Phase I study, Fimasartan (BR-A-657-K) 20mg ~ 480mg single dosing with healthy subjects, demonstrated that the Fimasartan (BR-A-657-K) was very safe and well tolerated. Another phase I study, Fimasartan (BR-A-657-K) 120mg and 360mg dosing for 7 days, also showed that Fimasartan (BR-A-657-K) was safe and tolerable though one temporal adverse event was observed in high dose.