Many traditional herbal remedies exhibit several beneficial effects including anti-inflammation. Panax notoginseng Buck F.H. Chen. is used as a therapeutic agent to stop haemorrhages and a tonic to promote health in Korean and Chinese medicine. The pharrnacokinetic profiles of the main P. notoginseng are still not accurately investigated. The exact mechanism of the anti-inflammatory action of P. notoginseng, however, has not been determined. In the present study, we examined the effect of P. notoginseng on lipopolysaccharide (LPS)-induced nitric oxide (NO) production, and inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene expression in RAW264.7 macrophages. The results indicated that P. notoginseng concentration-dependently inhibited LPS-induced NO production. Furthermore, P. notoginseng inhibited the expression of LPS-induced iNOS and COX-2 proteins without an appreciable cytotoxic effect on RAW264.7 cells. Berberine also inhibited LPS-induced iNOS protein as potently as P. notoginseng. This was consistent with the findings that P. notoginseng and also berberine inhibited prostaglandin E2 synthesis induced by LPS.