Morinda citrifolia (Noni) is a tropical plant whose leaves, barks, roots and fruits have been used as traditional remedy for various diseases. Although inflammation was considered as one of the indications for noni fruits, and fruit extract was demonstrated to have immunomodulatory activity in vitro, no principle has been identified. In our study, we attempted to identify constituents that may be responsible for antiinflammatory activity, and to elucidate the possible roles on anti-inflammatory mediators for interested compounds. Solvent extraction and column chromatography were major techniques used for isolation of compounds, while structures were elucidated by integration of data from UV, IR, MS and NMR analysis. Anti-inflammatory activity was assessed by mouse ear edema model. Subsequent Elisa analysis was carried out for their effects on anti-inflammatory mediators such as IL-Iβ, IL-6, PGE2 and myeloperoxidase. Scopoletin, quercetin, ursolic acid were identified as major antiinflammatory constituents. Since ursolic acid was known to have anti-inflammatory activity, we characterized the mode of action of scopoletin and quercetin in mouse ear inflammation model. The most potent inhibition occurred at 0.5 μmol level.