This study was done to know the effect of Giyuetang on the inflammatory response, contact hypersensitivity (CH), and rosette forming capacity of spleen cells. The effects of Jiyutang with Fructus Immaturus Ponciri on the inflammatory response were evaluated by measuring the production of such reactive oxygen intermediate(ROI) as $O_2^-$ and $H_{2}O_2$ in the peritoneal neutrophils and macrophages. The effects of Jiyutang with Fructus Immaturus Ponciri on the CH were evaluated by checking the ear swelling response against dinitrofluorobenzene(DNFB). The administration of Jiyutang with Fructus Immaturus Ponciri on the mouse decreased the amount of ROI in both neutrophils and macrophages. Jiyutang with Fructus Immaturus Ponciri depressed CH without affecting the rosette forming capacity of spleen cells. The results of this study showed that Jiyutang with Fructus Immaturus Ponciri might have anti-inflammatory effects by decreasing the amounts of ROI in the phagocytes and suppressing the CH, without affecting the rosette-forming capacity of spleen cells.