Abstract: Objective To investigate the clinical efficacy of long-term inhalation of N-acetylcysteine solution in patients with non-cystic fibrosis bronchiectasis,and provide feasible long-term drug regimen for patients to control the symptoms and reduce acute exacerbations. Methods Clinical data about patients diagnosed as bronchiectasis in the first medical center of Chinese PLA General Hospital from January 2014 to July 2018 were retrospectively reviewed.According to different treatment schemes,patients were divided into control group with routine anti-infection and expectorant treatment in acute phase without inhalation of N-acetylcysteine solution,and observation group with long-term inhalation of N-acetylcysteine solution in stable stage for at least 2 months on the basis of treatment in control group.During the follow-up,times of acute exacerbation,cough symptoms,sputum characteristics,sputum volume changes,dyspnea score and pulmonary function changes before and after treatment between the two groups,whether benefits were existed for long-term users were explored. Results The forced expiratory volume in one second (FEV1),forced vital capacity (FVC),actual FEV1/predictive FEV1,and actual FVC/predictive FVC in the observation group increased by 0.11 L,0.13 L,4.22%,3.33% after medication,while they decreased by 0.07 L,0.24 L,1.3%,6.19% in the control group,respectively,which showed significant differences between the two groups in all the indicators (all P<0.05).In terms of the change in score of sputum volume (-1 vs 0) and times of acute exacerbations (-2 vs 0),the observation group was significantly greater than the control group (P<0.05,respectively). Conclusion For patients with non-cystic fibrosis bronchiectasis,long-term aerosol inhalation of N-acetylcysteine solution can significantly improve the clinical symptoms,reduce the times of acute exacerbations and delay the deterioration of pulmonary function to a certain extent.