The objective of this study is to detect the effect of beta-glucan derived from Aureobasidium pullulans SM-2001, a UV induced mutant of A. pullulans on the ovalbumin (OVA) induced allergic asthma. The test articles were orally administered to OVA-inducing asthmatic mice 4 days after sensitization for 13 days at 31.25, 62.5 or 125 mg/kg levels. Three days after the OVA sensitization, ten mice were selected per group based on body weight and were sacrificed three days after the OVA aerosol challenge. The changes on the body weight, lung weight, total leukocytes in peripheral blood and total cells in bronchoalveolar lavage fluid (BALF) were observed with changes on the lung histopathology and histomorphometry. The results were compared with dexamethasone (DEXA) 3 mg/kg intraperitoneally treated mice. The results showed increases of body weight after the OVA aerosol challenge, lung weight, total leukocytes and eosinophils in peripheral blood, total cell numbers, neutrophil and eosinophils in BALF were detected in the OVA control compared to sham control (non-OVA). However, these changes from asthmatic responses were significantly or dose-dependently decreased in the beta-glucan-dosing groups compared to those of the OVA control. Therefore, it is concluded that beta-glucan has favorable effects on asthmatic response induced by OVA. It was found that beta-glucan 125 mg/kg showed similar or slightly lower efficacy compared with DEXA 3 mg/kg.