Objectives : The fresh young leaves and dried fruits of Zanthoxylum piperitum (Korean name: Chopi) are used as diuretics, stomachies, anthelmintic and for the treatments of disorders of the digestive organ in Asia. We investigated inhibitory effects of Zanthoxylum piperitum extract on lipopolysaccharide(LPS)-induced production of nitric oxide(NO) and pro-inflammatory cytokines including $TNF-{alpha}$ and $IL-1{eta}$ from RAW264.7 mouse macrophage cells. Methods : After methanol extract of Zanthoxylum Fructus (Zanthoxylum extract) was pretreated in RAW264.7 cells, the cells were stimulated with LPS. Cell toxicity of Zanthoxylum extract was assayed bv MTT assay. The production of NO from the cells was measured in culture medium by Griess reaction. The production of $TNF-{alpha}$ and $IL-1 ;{eta}$ from the cells was measured in culture medium by ELISA. Results : Zanthoxylum Fructus extract greatly inhibited the production of inflammatory mediators such as NO, $TNF-{alpha}$ and $IL-1{eta}$ from LPS-stimulated RAW264.7 cells. Conclusion : This result suggests that Zanthoxylum extract may have an anti-inflammatory effect through the inhibition of inflammatory mediators.