Sedum kamtschaticum Fischer (Crassulaceae) has been used as a folk medicine in North-East Asia for treating inflammatory disorders. The present investigation was carried out to establish in vivo anti-inflammatory activity and cyclooxygenase-2 modulating activity of this plant material. The methanol extract of Sedum kamtschaticum significantly inhibited mouse croton oil-induced ear edema (24-47% inhibition at 50-400 mg/kg) and rat paw edema (24-30% inhibition at 400-800 mg/kg) by oral administration. Prednisolone (10 mg/kg) showed 54 and 36% inhibition in the same animal models, respectively. Sedum kamtschaticum also showed significant inhibitory activity against mouse ear edema induced by multiple treatment of phorbol ester for 3 days. In addition, Sedum kamtschaticum exhibited potent analgesic activity against mouse acetic acid-induced writhing (IC50=125 mg/kg), while aspirin (200 mg/kg) showed 57% inhibition. Using lipopolysaccharide-treated RAW 264.7 cells, down-regulation of cyclooxygenase-2 expression was found to be one of the cellular action mechanisms of anti-inflammation by Sedum kamtschaticum.