Background : Traditional herbal medicine is used extensively among the Korean populations, and other Asian countries employ similar therapies as well. In recent years, extensive focus was laid on adulteration of the herbal medicine with liver damage. The use of herbal preparations as remedies for various medical conditions has continuously increased in Korea. Large proportions of Korean patients use herbal medicinal products, folk remedies, and health food. However, studies on the safety of herbal products are conducted on a less than sufficient basis even in the countries like Korea where herbal medicine is being used extensively. Some of the reports on the safety of herbs were done by the doctors of western medicine but lack of knowledge and misclassification led to misunderstandings. Objectives : This study aims to verify the evidences on safety of frequently used 4 herbal medications (Sipjeondaebo-tang, Bojungikgi-tang, Ohjeok-San, Yukmaijihwang-tang) in the lab animal model. Methods : Sprague-Dawley rats was treated by 4 herbal medications during 31 days. After 1 month, we checked body weight, liver weight, and serum enzyme associated with liver function. Results : There is no significant difference in body weight and liver weight after 1 month of administrations. In all experimental groups, no abnormal findings was observed in histotogical research and lab liver Functions test(AST, ALT etc). Conclusions : These four herbal medications, frequently used in oriental medicine clinics and hospitals, are safe from hepatoxic events in the lab animal model.