Objectives : Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by eczematous inflammtion of the skin. The chestnut inner shell extracts (CI) has been used as a cosmetic material for a long time in Korea. However, the precise anti-allergy effects of CI have yet to be clearly elucidated. In this study, we attempted to evaluate the effect of CI on mast cell-mediated allergy inflammation. Methods : To find the anti-allergy and inflammatory effect of CI, we investigated the inhibitory effect of CI on the production of inflammatory mediators using by enzyme-linked immunosorbent assay in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore (A23187) stimulated-human mast cell (HMC-1). Results : In this study, we found that CI did not show cytotoxic effect at up to 10 ug/ml on HMC-1. CI inhibited the production of tumor necrosis factor (TNF)-${alpha}$, interleukin (IL)-6 and IL-8 in stimulated HMC-1. Maximal rate of TNF-${alpha}$, IL-6 and IL-8 inhibition by CI (10 ug/ml) were about 47.6%, 44.1% and 22.5% respectively. In addition, we showed that Fr.3 isolated from n-Butyl alcohol layer of CI attenuated the production of TNF-${alpha}$, IL-6 and IL-8 in HMC-1. Conclusion : Taken together, the findings of this study provide us with a novel insight action of CI as a potential molecule for use in the treatment of allergic inflammation diseases.