Antiinflammatory activities of the solvent fractionates of several herbal medicines were investigated and SKI306X was prepared from the active principles of three herbal medicines, Prunella vulgaris, Trichosantlies kirilowii and Clematis mandshurica. SK1306X was shown to have strong inhibitory effects on acetic acid-induced pain, carrageenan-induced paw edema and adjuvant induced arthritis. LD50 of SKI306X was more than 5 g/kg in rat, so generally nontoxic. Chemical analysis revealed that oleanolic acid and rutin, which are known to have various antiinflammatory activities, were contained in it. These results suggest SK1306-X may become a useful drug for the treatment of inflammatory diseases such as rheumatoid arthritis.