Abstract： Objective:To evaluate whether the acute exacerbation of chronic obstructive pulmonary disease (AECOPD) caused by different causes would result in the severity difference in AECOPD following the stable stage.Methods:It was a prospective cohort study involving 155 AECOPD patients hospitalized in Shenzhen Second People′s Hospital who were non-randomly enrolled from September 2019 to January 2021.The demographic characteristics, complications, COPD Assessment Test (CAT) and Modified Medical Research Council (mMRC) Dyspnea Scale were recorded.Pulmonary function indexes, etiology and inflammatory indicators were detected.According to the etiology test results, patients were divided into bacterial infection group ( n=65), viral infection group ( n=58) and non-infectious group ( n=32).A one-year followed-up was performed after discharge.The annualized rate of COPD exacerbations and time to the first serious acute exacerbation were observed.The risk of re-exacerbation of COPD was identified by univariable and multivariable logistic regression analysis. Results:The proportion of eosinophils (EOS%) in the non-infectious group was significantly higher than that in the bacterial group and the virus group ([3.3±0.4]% vs [1.9±0.3]% vs [2.2±0.2]%, P=0.028, respectively).Neutrophil/lymphocyte ratio was significantly higher in bacterial infection group than that in viral infection group and non-infectious group (9.0±0.9 vs 4.1±0.4 vs 4.4±1.0, F=12.60, P<0.001, respectively).No significant differences in symptom scores, lung function and combination diseases were detected among three groups (all P>0.05).A total of 132 severe acute exacerbations of COPD in 71/155 AECOPD patients were recorded.There was no significant difference in the time of the first severe acute exacerbation and the number of severe exacerbations among the three groups (all P>0.05).Multiple logistic regression showed that the number of acute exacerbations within one year, the number of all-cause hospitalizations within one year and the combination of respiratory failure were significantly correlated with severe acute exacerbations within one year. Conclusions:There is no difference in the effect of acute exacerbation of COPD caused by different inducements on the future acute exacerbation.Prevention of all causes of acute exacerbation is equally important for patients with COPD.