In order to validate the use of Saussurea Lappa as an anti-inflammatory drug in the traditional Korean medicine, I have investigated the effects of water-soluble extract of Saussurea Lappa (ESL) on the production of pro-inflammatory tumor necrosis factor-alpha (TNF-α) in murine RAW 264.7 macrophages stimulated with the endotoxin lipopolysaccharide (LPS). The extract inhibited dose-dependently TNF-α production without its cytotoxic effect on the macrophages, as measured by enzyme-linked immunosorbent assay, and significantly decreased mRNA levels of TNF-α, as determined using reverse transcription polymerase chain reaction. The extract also inhibited LPS-induced activation of nuclear factor- κB, thereby resulting in TNF-α gene expression. These results suggest that ESL may have therapeutic potential in the control of inflammatory diseases mediated by activated macrophages.