Panax ginseng C.A. Mayer (Araliaceae, P. ginseng) has been used for the enhancement of vascular and immune functions in Korea and Japan for a long time. Ginsenoside $Rb_1$ and $Rg_3$ isolated from P. ginseng head-part butanolic extract (PGHB) were investigated for anti-inflammatory activity. Ginsenosides and PGHB did not affect the cell viability within $0;-;100;{mu}g/ml$ concentration to RAW 264.7 murine macrophage cells. Ginsenosides and PGHB inhibited partly lipopolysaccharide (LPS)-induced nitrite production in a dose-dependent manner. The ginsenosides and PGHB showed partially chemical nitric oxide (NO) quenching (maximum 40%) in the cell-free system. Also, ginsenoside $Rb_1$ and $Rg_3$ inhibited markedly approximately 74 and 54% of inducible nitric oxide synthase (iNOS) mRNA transcription from LPS-induced RAW 264.7 cells. Taken together, the inhibitory effect of ginsenosides and PGHB on NO production did not occur as a result of cell viability, but was caused by both the chemical NO quenching and the regulation of iNOS. Additionally, the ginsenoside $Rb_1$ and PGHB inhibited prostaglandin $E_2$ ($PGE_2$) synthesis in a concentration-dependent manner, showed approximately 70-98% inhibition at $100;{mu}g/ml$ concentration. And the treatment with ginsenosides and PGHB attenuated partially LPS-upregulated cyclooxygenase-2 (COX-2) gene transcription. Ginsenoside $Rg_3$ suppressed LPS-stimulated interleukin-6 (IL-6) level to the basal in RAW 264.7 cells. From these results, ginsenoside $Rb_1,;Rg_3$, and PGHB may be useful for the relief and retardation of immunological inflammatory responses and its action may occur through the reduction of inflammatory mediators, including NO, $PGE_2$, and IL-6 production.