In general, Reucedani Radix (Peucedanum japonicum Thunbergis: PJ) is the Korean traditional herbal medicine used to remove dampness, to relieve pain, and spasm. So, PJ folium is believed to have the same effects. The aim of this study is to investigate the alleviation of dextran sulfate sodium (DSS) induced ulcerative colitis in mice by PJ folium. 25 mice were divided into 5 groups: normal, DSS, DSS + 100 mg/kg PJ folium (PJ100), DSS + 500 mg/kg PJ folium (PJ500), and DSS + 150 mg/kg 5-amino salicylic acid (5-ASA) groups. Body weights, colon lengths, histological changes in colon tissue, and spleen weights were observed. Inflammatory cytokines such as IL-$1{eta}$, IL-6, and TNF-${alpha}$ level in plasma were measured by ELISA. IL-$1{eta}$, IL-6, and TNF-a mRNA expression in colon tissue were detected by RT-PCR. In the results, body weight lose was inhibited in PJ100, PJ500, and 5-ASA groups, but it was not different compared with DSS group, significantly. PJ500 group showed the preventive effects of colon length shorten and histological changes in colon tissues as good as 5-ASA group. The weight of spleen was increased in DSS group but it reduced in PJ100, PJ500, and 5-ASA groups. Moreover, IL-$1{eta}$ and TNF-${alpha}$ cytokine levels in plasma were reduced in PJ500 and 5-ASA groups. IL-$1{eta}$, IL-6, and TNF-a mRNA expression in colon tissue were inhibited in PJ100, PJ500, and 5-ASA groups and it was significantly different compared with DSS group. In conclusion, PJ folium showed the alleviative effect on DSS induced ulcerative colitis in mice.