The effect of Ginseng root on experimentally induced hypertension in rat was investigated. The results are concluded as follow; 1) We failed to produce hypercholesterolemic hypertension in rats of cholesterol (20 mg/kg) feeding for 60 days. 2) Ginseng supressed the increased blood pressure which induced by thyroxine treatment for 5 days of 1.0 mg/kg does during cholesterol feeding. 3) Ginseng per se revealed slightly increased blood pressure in normal and cholesterol fed rats. 4) No pathological changes were found macroscopically and microscopically in aorta of all experimental animal. 5) It is suggested that Ginseng has no direct action on peripheral vascular wall but plays a some role on centrally mediated mechanism. The confirmatory experiment should be performed.