Korean Sophora japonica has been found to posses an anti-inflammatory activity. In this study, Korean Sophora japonica extract, rutin, was used to know whether rutin inhibits to produce inflammatory mediators NO and TNF-$alpha$ from the mouse peritoneal macrophages that were treated an inflammatory agent LPS. The rutin-1 hr pretreated macrophages were incubated with LPS for 0.5~5 hrs, and then collected the supernatant and the cell lysate for measurements of the level of iNOS, NO, TNF-$alpha$ mRNA, TNF-$alpha$, and p-NF-${kappa}B$. Minimal and maximal effective doses of the rutin on them were 1 and $100{mu}g/ml$, respectively. The maximal effective dose of rutin certainly inhibted the productions of iNOS, NO, TNF-$alpha$ mRNA, TNF-$alpha$and p-NF-${kappa}B$ from the LPS-treated macrophages (p<0.0001). Its $ED_{50}$ for inhibition of TNF-$alpha$ mRNA and p-NF-${kappa}B$ was $5{mu}g/m{ell}$, and for iNOS, NO, and TNF-$alpha$ was $10{mu}g/m{ell}$. The rutin did not have any cytotoxic effect. As the results, the Sophora japonica rutin could be a good candidate for an anti-inflammatory action.