Objectives : Betula Platyphylla(BP) is a traditional analgesic, anti-fungal, anti-inflammatory herb used in Chinese 1medicine. However, no information is available to explain its action. In this study. we investigated the anti-inflammatory 1effects of BP to elutidate the molecular pharmacological activity in the ethanol extract of BP(BPE). Methods : We performed WTS assay in lipopolysaccharide (LPS) stimulated RAW264.7 macrophages with BPE. Nitrite was measured by Griess assay, prostaglandin E2 (PGE2) by enzyme-linked immunosorbent assay (ELISA) in LPS induced RAW264.7 macrophages with BPE. Inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) were determined by Western blot. Activation of nuclear factor-kappaB (NF-kB) was measured by electrophoretic mobility shift assay (EMSA). Results : BPE significantly suppressed production of nitric oxide (NO) and PGE2 in LPS-induced RAW264.7 macrophages in a dose-dependent manner. The maximal inhibition rate of NO and PGE2 production by BPE was ca. 88.8% and 93% at the concentration of $100{mu}g/ml$ (non-cytotoxic concentration), respectively. BPE also decreased iNOS protein and COX-2 protein in LPS-induced RAW264.7 macrophages. EMSA demonstrated that BPE inhibited the DNA binding activity of the NF-kB. Conclusions : These results suggest that BPE inhibits NF-${kappa}B$-mediated gene expression and downregulates inflammatory mediator production in RAW264.7 macrophages.