The effect of changes of airway inflammation on airway nonspecific reactivity were studied in 29 patients with chronic asthma. Detailed examinations of bronchial lavage (BAL) fluid and airway responses to histamine, propranolol and exercise were performed before and after treatment. The patients treated with steroids had significant improvements in parameters of BAL fluid cells and mediators with consistent changes of decreasing airway reactivities to propranolol and exercise after treatment. Whereas no significant changes occurred in the patients treated with B2-agonist either in inflammatory parameters or airway responses. On the other hand, airway response to histamine changed little in all asthmatic patients. Our study implied that inhibiting the airway inflammation in asthmatics may lead to marked decrease of airway response to non-mediator stimuli but fail to attenuate bronchial hyperresponse to mediator stimuli like histamine.