The purpose of this study is to observe the effect of Woogyuyem on serum reaction and hepatic tissue in Cyclosporin A treated rats. In this study, the experimental rats divided two group(Control group and Sample group). Under the same condition, both control group and sample group were injected to abdomen with Cyclosporin A for 7days. And then, control group were administered water, sample group were administered Woogy-uyeum for 300days. The change of transaminase and bile acid and SOD activity in blood serum, hepatic tissue were measured at 3rd, 7th, 15th, 30th day. The obtained results are summarised as follows : 1. In the change of SGOT contents, as compared with control group, sample group was significantly decreased at 7th and 15th day. 2. In the. change of SGPT contents, as compared with control group, sample group was significantly decreased at 15th day. 3. In the change of serum bile acid contents, as compared with control group, sample group was significantly decreased at 7th and 15th day. 4. In the change of serum SOD activity, as compared with control group, sample group was significantly increased at 15th and 30th day. 5. In the change of hepatic tissue, as compared with control group, the vacuolation of hepatocytes in the sample group was reduced, the liver plates were reconstructed, and the epitheriai cell wasn't destructed.