The anti-inflammatory activity of the aqueous extract from Gleditsiae spina was investigated utilizing carrageenin-induced edema, granuloma pouch and adjuvant arthritis in rats. The effects of this agent on vascular permeability and acetic acid-induced writhing in mice were also examined. Its anti-inflammatory activity on carrageenin edema was observed with oral administration. The aqueous extract from Gleditsiae spina(400 mg/kg, 7 days) showed significant inhibitory effects on granuloma and exudate formation in rats. In the method of adjuvant arthritis, the aqueous extract(400 mg/kg), orally administered for 21 days, inhibited the development of hind paw edema in rats. The aqueous extract was also inhibited the increase in vascular permeability and the number of writhings induced by acetic acid in mice. In the present study, the aqueous extract of Gleditsiae spina was indicated to have the anti-inflammatory action.