Objective : Juglandis Semen has a function that to invigorate the lung and kidney. And It is commonly used as a supporting agent in the treatment of coughing and bronchitis. This study was performed to investigate the effect of oral administration of Juglandis Semen Extract (JSE) against the experimental asthma induced by ovalbumin. Methods : Asthma was induced to Balb/c mouse by i.p. injection and aerosol immunization with ovalbumin. It was observed the change of the cell number in the BAL fluid. Concentrations of IL-4, IL-5 in splenoc yte were assessed by ELISA, IgG and IgE from serum were calculated by same method. Results : 1. Number of macrophage in BAL fluid was significantly decreased in JSE group compared with control group, but not eosinophil and lymphocyte. 2. Levels of IgG and IgE in serum were significantly decreased in JSE group compared with control group, respectively. 3. Concentration of IL-4 in culture supernatant of splenocyte was significantly decreased in JSE group compared with control group, but there was no significant in IL-5. Conclusion : We found that the effect of JSE extract in asthma was implicated in reduction of IL4released from Th2 cell, and decreases of IgG and IgE from plasma cell. These findings suggest that JSE can produce anti-asthmatic effect, which may play a role in allergen-induced asthma therapy.