The youngkaechulgamtang (Y) composed of four herb drugs, including Hoelen (H). Cinnamomi Ramulus (C). Atractylodis Rhizoma Alba (A) and Glycyrrhizae Radix (G). In oriental medicine literatures, Youngkaechulgamtang is described to be effective in headache, inflammation, uremia, gastritis, diarrhea and hypertension. To estimate the clinical effectiveness of Youngkaechulgamtang, several pharmacological experiments were carried out. The results are summerized as follows; On acetaminophen-induced hepatotoxicity, C+A, Y-G, Y-H, MIX and Y showed the significant elevation of glutathione-S-transferase. But, C+A, Y-G, Y-H, MIX and Y showed the significant suppression of serum aminotransferases. On ANIT-induced cholestasis, U (Ursodesoxycholic acid 50 mg/kg)+$Y_l$ (760 mg/kg) showed the significant increase of bile juice volume. $Y_l,;Y_2$ (1520 mg/kg), U, $U+Y_l$ showed the remarkable increase of cholic acid. U and $U+Y_l$ showed the significant decrease of total bilirubin. From these results, it is suggest that Y shows liver protective effect against various hepatic injury. Especially, Youngkaechulgamtang was more effective than mixture of 4 ingredients in the elevation of glutathione-S-transferase in acetaminophen-induced hepatotoxicity.