Objective : Houttuyniae Herba is widely used in oriental medicine as a remedy for inflammation. However, as yet there is no clear explanation of how Houttuyniae Herba affects the production of inflammatory cytokine. This study was to determine the effects of Essence extracted from Houttuynia cordata Thunb(HCT) on the mast cell-mediated inflammatory responses. Method : We measured the amount of inflammatory cytokine production induced by the phorbol myristate acetate (PMA) plus calcium ionophore(A23187) in the human mast cell line (HMC-1) incubated with various concentrations of HCT. The TNF-$alpha$, IL-6 and IL-8 secreted protein levels were measured by the ELISA assay. The TNF-$alpha$, IL-6 and IL-8 mRNA levels were measured by the RT-PCR analysis. Nuclear and cytoplasmic proteins were exmined by Western blot analysis. The NF-$kappa$B promoter activity was examined by a luciferase assay. Result : HCT inhibited the PMA + A23187-induced TNF-$alpha$, IL-6 expression and reduced mRNA of TNF-$alpha$, IL-6 and IL-8. we observed that HCT suppressed the induction of NF-B activity. In addition, HCT suppressed PMA plus A23187-induced NF-$kappa$B promoting activity. Conclusion : In this study, we have found that HCT is an inhibitor of NF-$kappa$B and cytokines on the mast cell-mediated inflammatory responses.