This study evaluated the effect of maximal oxygen pulse (O 2P max) on patients with chronic obstructive pulmonary disease (COPD) and confirmed the predictive effect on acute exacerbations of COPD (AECOPD).This retrospective study included 91 participants who underwent cardiopulmonary exercise testing (CPET), lung function testing, a dyspnea scale assessment, and a 3-year follow-up. The participants were divided into two groups according to the O 2P max value. Exercise capacity, ventilatory conditions, gas exchange efficiency, and dyspnea symptoms were compared, and the correlations between O 2P max and these indices were evaluated. The ability of O 2P max to predict AECOPD was examined.Exercise capacity, ventilatory conditions, and gas exchange efficiency were lower, and dyspnea symptom scores were higher in the impaired O 2P max group ( P < 0.05). O 2P max was positively correlated with forced vital capacity (FVC)%, forced expiratory volume in 1 sec (FEV 1)%, FEV 1/FVC%, anaerobic threshold (AT), work rate (WR)%, aximal oxygen uptake (V̇O 2max)%, V̇O 2/kg max, V̇O 2/kg max%, WR AT, WR max, V̇O 2AT, V̇O 2max, and V̇ Emax, and was negatively correlated with EqCO 2AT, and EqCO 2max ( P < 0.05). Most importantly, O 2P max could be used to predict AECOPD, and the best cut-off value was 89.5% (area under the curve, 0.739; 95% CI, 0.609-0.869).O 2P max reflected exercise capacity, ventilation capacity, gas exchange capacity, and dyspnea symptoms in patients with COPD and may be an independent predictor of AECOPD.Copyright © 2022 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.