Abstract： Objective:To evaluate the clinical characteristics and exacerbation risk of different phenotypes of acute exacerbation of chronic obstructive pulmonary disease(AECOPD) based on granulocyte classification of peripheral blood eosinophils and neutrophils.It is of great significance to personalized treatment and prognosis improvement.Methods:This was a cohort study.Using a non-random control method, a total of 448 patients with AECOPD admitted to the Department of Respiratory and Critical Care Medicine, the Second Affiliated Hospital of Chongqing Medical University, from October 2019 to June 2021 were selected.According to the peripheral blood cell level at admission, the patients were divided into eosinophil group ( n=158), neutrophil group ( n=174), mixed granulocyte group ( n=46), and hypogranulocyte group ( n=70).The clinical characteristics during the hospital stay was compared, recurrent exacerbation requiring hospitalization within one year was used as follow-up outcome, all patients were followed up for 1 year, Kaplan-Meier survival curve was plotted, and Cox regression analysis was performed to evaluate the risk factors. Results:During hospitalization, the incidence of respiratory failure was statistically significant ( P=0.043).The usage of intravenous glucocorticoids and advanced antibiotics was the highest in the neutrophil group and lower in the eosinophil group (48.3% vs 31.0%, 33.3% vs 7.0%, P<0.05).The Kaplan-Meier survival curves showed that the rate of recurrent acute exacerbation was the highest in the neutrophil group, followed by the mixed granulocyte group, and lower in the eosinophil group and hypogranulocyte group ( P=0.003).With the eosinophil group as the control group, the risk of recurrent acute exacerbation was higher in the neutrophil group ( HR=1.95, 95% CI: 1.13-3.37, P=0.017).Other exacerbation factors included age ( HR=1.04, 95% CI: 1.01-1.07, P=0.005), FEV 1%pred ( HR=0.98, 95% CI: 0.96-0.99, P=0.002) and ICS ( HR=1.61, 95% CI: 1.01-2.57, P=0.046). Conclusions:Based on granulocyte classification of peripheral blood eosinophils and neutrophils, neutrophil AECOPD is more severe than eosinophil AECOPD during hospitalization and has a higher risk of recurrent acute exacerbation.