Objective: Yang Geouk San Hwa - Tang (YGSHT) has been widely used in Sasang Constitutional Medicine of Korea for treatment of acute inflammatory symptom, such as palatine tonsillitis, polydipsia, headache, papule, pimple however, the mechanism of its anti-inflammatory activity has not been clarified. In this study, therefore, we investigated the mechanism of the inhibitory effect of YGSHT on LPS-induced inflammation. Materials and methods: The effect of YGSHT was analyzed by ELISA, RT-PCR and Western blotting in LPS-stimulated RAW264.7 cells. Results: We found that YGSHT suppressed not only the production of pre-inflammatory cytokines (IL-$1{eta}$ and TNF-$alpha$), the generation of nitric oxide (NO) and prostaglandin E (PGE)2, but also the mRNA expression of pre-inflammatory cytokines, inducible nitric oxide synthase (iNOS), and cyclooxygenase (COX)-2. Furthermore, YGSHT was shown to inhibit the phosphorylation of ERK1/2 and JNK1/2 and the activation and translocation of NF-kB from cytosol to nuclear in LPS-stimulated RAW264.7 cells. Conclusions: These results suggest that YGSHT exerts an anti-inflammatory effect through the regulation of the ERK1/2 and JNK1/2 pathway and NF-kB pathway, thereby decreasing production of pre-inflammatory cytokines, NO, and PGE2.