Ellagitannins have been reported to enhance the immune system. In this study, the effects of pedunculagin on langerhans cells were examined. Pedunculagin, an ellagitannin from Alnus hirsuta var. microphylla. Betulaceae, is a novel immunomodulator. Langerhans cell are known as the potent antigen presenting cell and elicit the Contact Hypersensitivity (CHS) response by presenting Ag to trafficking Ag-specific T cells within the skin. For determining the effects af pedunculagin on murine langerhans cell, the expression of TNF-$alpha$ mRNA was examined by RT-PCR. As a result, the expression of TNF-$alpha$ mRNA was upregulated by pedunculagin. These results suggest that pedunculagin enhances TNF-$alpha$ and could be used as an immunomodulator in skin immune system.