The present study was conducted to evaluate the effect of methanolic extracr of B.sensitivum on mast cell Degranulation induced by Egg albumin, the antioxidant activity, differential WBC count in BAL fluid and histopathology of lungs in ovalbumin induced lung inflammation in an animal model of asthma. The methanolic extract of aerial part of Biophytum sensitivum (MBS) was prepared. Animals were divided into 6 groups (Normal control, Disease control, Standard group (Dexamethasone-4mg/kg) and Treatment groups (MBS-100 mg/kg, 200 mg/kg, and 400 mg/kg) in Ovalbumin induced model. Ovalbumin was given by i.p on days 7 and 14, by aerosol on days 28 to 30. Treatment groups and the Standard group were treated orally for last 10 days with MBS (100 mg/kg, 200 mg/kg and 400 mg/kg) and Dexamethasone (4mg/kg) respectively. In Egg albumin induced mast cell degranulation model, mast cell derived from mesentery divided into 6 groups including MBS at doses 50 µg/gm, 100 µg/gm, 200 µg/gm. Percentage protection of mast cells was calculated. Antioxidant activity was done for lung homogenate. Results were analyzed by using one way ANOVA. Methanolic extract of Biophytum sensitivum (400mg/kg) significantly (p