Scoparone is a major component of the shoot of Artemisia capillaris (Compositae), which has been used for the treatment of hepatitis and biliary tract infection in oriental countries. In the present study we observed that, scorparone exhibited no cytotoxic effect in unstimulated macrophages, but reduced the release of nitric oxide (NO) and prostaglandin $E_2;(PGE_2)$ upon stimulation by IFN-${gamma}$/LPS or LPS. The inhibitory effects were found to be in conjuction with the suppression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in IFN-${gamma}$/LPS stimulated RAW 264.7 cells. Moreover, scoparone also attenuated the production of tumor necrosis factor (TNF)-${alpha}$, interleukin (IL)-$1{eta}$ and IL-6 in LPS-stimulated RAW264.7 cells. These results suggest that scoparone decreases the production of the inflammatory mediators such as NO and $PGE_2$ in macrophages by inhibiting iNOS and COX-2 expression.