Objective: This study was carried out to evaluate the inhibitory effect on immme hypersensitive reaction by Yangdokbackhotang extract. methods: To study, We divided 4 weeks old rats into three groups of 20, which are the constrasive group with nothing treated, the skin transplated only, and the Yangdokbackhotang extract fed before skin transplantation. And did the experiment. Results: 1. The ear swelling in mice treated with YB noticeably decreased than only DNCB treated mice. 2. As shown in Table3, also results in a significant decrease of YB group than ST group in the number of positive cells of $NF-{kappa}B$, COX-2, IL-12B, and ICAM-1. From the above results, it could be concluded that Yangdokbackhotang showed benificial immunosupressive effect on the hypersensitive reaction.