Objective : The aim of this study was to determine whether methanol extract of Keum-Ryung-Ja-San (KRJS) inhibit production of NO, $PGE_2$, iNOS, COX-2 and pro-inflammatory cytokines in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. Methods : Cytotoxic activity of extracts on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. The nitric oxide (NO) production was measured by Griess reagent system. And proinflammatory cytokines and PGE2 were measured by ELISA kit. The levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2(COX-2), $I{kappa}-B-alpha$ and nuclear NF-${kappa}B$ p65 expression were detected by western blot. Results : Our results indicated that methanol extract of KRJS significantly inhibited the LPS-induced NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of TNF-$alpha$, IL-$1{eta}$ and IL-6 production in RAW 264.7 cells. Moreover, methanol extract of KRJS treatment also blocked LPS-induced NF-${kappa}B$ activation. Conclusion : These findings indicate that methanol extract of KRJS inhibits the production of pro-inflammatory mediators and cytokines via suppression of NF-${kappa}B$ activation. Take together, these results indicate that methanol extract of KRJS has the potential for use as an agent of anti-chronic inflammatory diseases.