In order to investigate the protective effect of Samduhaejungtang on the liver injury of rats induced by $CCl_4$ and d-galactosamine, the serum transaminase(GOT& GPT), alkaline phosphatase(ALP), lactic dehydrogenase(LDH) for enzyme activities and triglyceride, total bilirubin amounts for serum component were measured. All animals were divided into 4 groups, those were normal group(untreated), control group(treated with vehicle 0.9% Saline solution), sample Ⅰ group(1000mg/kg administrated), sample Ⅱ group(2000mg/kg administrated). The results were as follows : 1. The inhibitory effects of the serum GOT activities in rats induced by $CCl_4$ were noted in both sample Ⅰ group(p<0.01) and sample Ⅱ group(p<0.001). In serum GPT activities, sample Ⅱ group(p<0.05) only showed the inhibitory effects. 2. The inhibitory effects of the serum ALP activities in rats induced by $CCl_4$ were noted in both sample Ⅰ group(p<0.01) and sample Ⅱ group(p<0.001). 3. The inhibitory effects of the serum LDH activities in rats induced by $CCl_4$ were noted in sample Ⅱ group(p<0.05). 4. The increases of the serum triglyceride content level in rats induced by $CCl_4$ were inhibited in both sample Ⅰ group(p<0.01) and sample Ⅱ group(p<0.001). 5. The increases of the serum total bilirubin content level in rats induced by $CCl_4$ were inhibited in both sample Ⅰ group(p<0.01) and sample Ⅱ group(p<0.001). 6. The inhibitory effects of the serum GOT& GPT activities in rats induced by d-galactosamine were noted in sample Ⅱ group(p<0.001), but sample Ⅰ group was not recongnized. 7. The significantly inhibitory effects of in the serum LDH activities in rats induced by d-galactosamine were note in sample Ⅱ group(p<0.05). 8. The increases of the serum triglyceride content level in rats induced by d-galactosamine were inhibited in sample Ⅱ group(p<0.01). 9. The increases of the serum total bilirubin content level in rats induced by d-galactosamine were inhibited in sample Ⅱ group(p<0.05). According to the above results, it is considered that Samduhaejungtang has protective effect against liver injury in rats induced by $CCl_4$ and d-galactosamine.