Traditionally, the thorns of Gleditsia sinensis LAM. (GS) have been used for the treatment of various types of cancer and heart, skin, vascular and inflammatory diseases. However, there have been no reports on the antinociceptive or antiinflammatory properties of the thorn of GS. The present study was carried out to evaluate the anti-inflammatory and antinociceptive effects of the ethanolic extract of GS (EEGS) and its sub-fractions. The administration of EEGS (500 mg/kg) or its butanolic fraction (50 and 100 mg/kg) reduced the frequency of the acetic acid-induced writhing reflex in mice. In addition, the administration of the butanolic fraction of EEGS (50 and 100 mg/kg) prolonged the latency of reaction at the hot plate in mice. The butanolic fraction of EEGS also inhibited lipopolysaccharide-induced nitric oxide, prostaglandin $E_2$, and tumor necrosis factor-$acute{a}$ production in the RAW 264.7 cell line. These results suggest that EEGS has anti-inflammatory and analgesic properties and is a potential therapeutic for inflammation and nociception.