In order to investigate the protective effects of Gami Yugan-tang on liver damage in rats induced by $CCl_{4}$ and d-galactosamine, the serum transaminase(ALT & AST), alkaline phosphatase(ALP), lactic dehydrogenase(LDH), superoxide dismutase(SOD), catalase, glutathione S-transferase(GST), glutathione peroxidase(GPX) for enzyme activities, and lipid peroxidation were measured. All animals were divided into 4 groups: normal group (untreated), control group (treated with 0.9% saline solution), sample I group (treated with 740mg/kg Gami Yugan-tang), and sample II group (treated with 1,480mg/kg Gami Yugan-tang). The results were as follows : 1. The results of liver damage in rats induced by $CCl_4$ : The protective effects of ALT were displayed in sample I and sample II, and AST, ALP, LDH, SOD, catalase, GST, GPX, and lipid peroxidation were noted in sample II group. It showed slight necrosis of hepatic cell and pathologic changes, for example, inflammatory cells infiltration were improved in sample II group compared to the control group. 2. The results of liver damage in rats induced by d-galactosamine : The inhibitory effects of AST, ALT, LDH, and ALP activities were noted in both sample I and sample II groups. The findings from this experiment suggests that Gami Yugan-tang has protective effects against liver damage in rats induced by $CCl_{4}$ and d-galactosamine.