The purpose of this study was to investigate the anti-inflammatory effects of water extract from Euonymus alatus (Thunb.) Sieb. (EAS) on the RAW 264.7 cells. To evaluate of anti-inflammatory of EAS, we examined the cytokine productions on lipopolysaccharide (LPS)-induced RAW 264.7 cells and also inhibitory mechanisms using Western blot. EAS reduced LPS-induced production of nitric oxide (NO), interleukin (IL)-1b, IL-6, IL-10 and tumor necrosis factor-a (TNF-a) in RAW 264.7 cells. EAS inhibited the activation of mitogen-activated protein kinases (MAPKs) such as p38, extracelluar signal-regulated kinase (ERK 1/2) and c-Jun NH2-terminal kinase (JNK) but not of inhibitory kappa B a (Ik-Ba) degradation in the LPS-stimulated RAW 264.7 cells. In conclusion, EAS down-regulated LPS-induced NO and cytokines production, which could provide a clinical basis.