OBJECTIVE: To observe changes in the lung function of asthmatic children with different symptoms during treatment, and to investigate the clinical significance of bronchial reversibility test in the treatment of asthma in children. METHODS: A total of 417 asthmatic children were treated by salmeterol/fluticasone inhalation for more than 3 months. These patients were divided into asymptomatic, single cough, paroxysmal cough and wheeze (cough+wheeze or wheeze alone) groups based on the symptoms when they revisited the clinic. Thirty-four healthy children were used as a control group. All children underwent bronchial reversibility test using nebulized salbutamol. Lung function testing was performed before and after the test. RESULTS: After nebulization of salbutamol, each asthma group showed significantly decreased rate of abnormal lung function and significantly increased forced expiratory volume in one second percent (FEV1%) predicted (P<0.05). Before salbutamol nebulization, the single cough, paroxysmal cough and wheeze groups had significantly higher rates of abnormal lung function and significantly lower FEV1% predicted than the control group (P<0.05). There were significant differences in the rate of abnormal lung function and FEV1% predicted among the asthma groups (P<0.05). After salbutamol nebulization, the paroxysmal cough and wheeze groups had significantly higher rates of abnormal lung function than the control group (P<0.05), but there were no significant differences between other asthma and control groups; the wheeze group had significantly lower FEV1% predicted than the control group, but no significant differences were found between other asthma and the control groups. The positive rate of bronchial reversibility test in each asthma group was significantly higher than in the control group (P<0.05). There were significant differences in the positive rate of the test between the asthma groups except between the asymptomatic and single cough groups (P<0.05). CONCLUSIONS: Asthmatic children with different symptoms demonstrate different lung functions during treatment. Bronchial reversibility test combined with lung function test is useful in assessing asthma control and guiding treatment.