Abstract： Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is an important event triggered mostly by environmental pollutants and respiratory infections, which is a major driver for the poor outcomes of chronic obstructive pulmonary disease.Frequent exacerbations of chronic obstructive pulmonary disease are associated with the accelerated decline in lung function, impaired quality of life, and increased mortality.Biomarkers are promising to assess disease condition and contribute to classify subtypes.However, the diagnostic criteria and treatment principles of AECOPD are still controversial.This review summarizes the current epidemiology of AECOPD, the burden of the disease, and the challenges in the clinical management.