Objective : This study was performed to investigate the effect of oral administration of Oldenlandiae Diffusae Herba (ODH) on eosinophil, immunoglobulin-E and interleukin-4 in 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 eosinophil number in the BALF. And, it was observed the change of the concentrations of IL-4 in BALF and splenocyte, IgE in serum by ELISA. Results : 1. The number of eosinophil in BALF was significantly decreased in ODH group copared with control group. 2. Concentration of IL-4 in serum, BALF and splenocyte was significantly decreased in ODH group compared with control group, respectively. 3. Level of IgE in serum was significantly decreased in ODH group compared with control group. Conclusion : We found that the effect of ODH extract in asthma was implicated in reductions of IL-4 released from Th2 cell, and decreases of IgE from plasma cell. These findings suggest that ODH extract can produce anti-asthmatic effect, which may playa role in allergen-induced asthma therapy.