Objective To evaluate the clinical efficacy of Bufei Granules and to explore its possible mechanism in treating asthma in remission stage. Methods Sixty seven patients with asthma in remission stage were randomly assigned to treatment group with 33 cases and control group with 34 cases. The treatment group was given Bufei Granules

while the control group was given Bufei Granules mimetics

both for 6 g each time

3 times per day. The course was 1 month with a 3-month follow up. Scores of TCM syndrome and asthma control test（ ACT） were recorded before and after the treatment

as well as during follow-ups. Levels of exhaled nitric oxide（ Fe NO） and pulmonary function indexes were detected

and frequencies of the use of bronchodilators and acute attacks were observed.Results After treatment and during follow-ups TCM syndrome scores in the treatment group were significantly decreased

while ACT scores was significantly increased

and the improvement was better than that in the control group（ P < 0. 05 or P < 0. 01）. Fe NO levels were decreased in both groups after treatments

and the decrease in the treatment group was superior to that in the control group（ P < 0. 05 or P < 0. 01）. During the follow-ups

frequency of the use of bronchodilators significantly reduced in both groups compared with before treatment

expecially in the treatment group（ P < 0. 05 or P < 0. 01）. There were no significant differences in pulmonary function indexes and the occurrence of acute attacks during the follow-ups between the two groups（ P > 0. 05）. Conclusion Treating asthma in remission stage with Bufei Granules can significantly improve symptoms

reduce Fe NO level and suppress airway inflammation

so as to reduce the occurrence of acute asthma attacks.