Background：Chronic Obstructive Pulmonary Disease（COPD) is an inflammatory airway disease MESHD characterized by the presence of expiratory flow limitation. Exacerbations of COPD are common acute events. During epidemic of COVID-19, concerns have been raised with regard to mask- using because of increasing respiratory resistance. In this study, we aimed to evaluate the relationship between the vital signs , inflammation MESHD index, hypercapnia MESHD hypercapnia HP, hypoxia MESHD and mask-using in AECOPD patients.Methods：This retrospective study was performed at a tertiary hospital, and enrolled 23 patients with AECOPD who were hospitalized three or more times in the respiratory department. Patients in Group C were hospitalized and used masks during the epidemic period of COVID-19. Patient’s data of the previous two hospitalizations from the medical record system divided into group A and group B according to the time sequence. Vital signs, inflammation MESHD index, artery blood SERO gas from medical record system and questionnaires of three hospitalizations in the same patient were collected to perform paired test.Results: Surgical mask using increased the levels of PaCO2 (8.98mm Hg; p = 0.004), HCO3-act (4.1mmol/L; p =0.006), BE (3.01mmol/L; p =0.019) and systolic blood SERO pressure (11.39mm Hg; p = 0.01) in patients with AECOPD compared to last hospitalization. Surgical mask using for 30 to 120 minutes is associated with hypercapnia MESHD hypercapnia HP. There were no significant differences observed between group B and group A without using mask in vital signs, inflammation MESHD index, and artery blood SERO gas.Conclusions: In this study, we found that systolic blood SERO pressures and PaCO2, HCO3-act, BE were significantly elevated in AECOPD patients using masks compared to the other groups without masks. In addition，the changes in PaCO2,HCO3-act,BE is closely related to serum SERO chloride concentration. Therefore, it is need to increase awareness and understanding of the use of masks in patients with chronic cardiopulmonary diseases MESHD.