Abstract： Objective:To explore the influence of airway mucus plugs on patients with bronchial asthma and its management.Methods:In this cross-sectional study, from January 2020 to June 2022, 100 patients who were diagnosed with asthma and underwent chest CT examination in the Outpatient Department of Peking University Third Hospital were included. The chest CT results and medical history, pulmonary function, fractional exhaled nitric oxide (FeNO), blood routine, total allergen IgE, Aspergillus fumigatus M3 allergen-specific IgE antibody test results were collected. According to the results of chest CT, the asthma patients were divided into group with mucus plugs and those without mucus plugs. Distribution of airway mucus plugs and the mucus plug scores based on lung segments were calculated. The relationships of mucus plugs with medical history, pulmonary function [These included before and after the bronchodilation test, forced vital capacity percent of predicted value (FVC%pred), forced expiratory volume in one second percent of predicted value (FEV 1%pred), FEV 1/FVC, peak expiratory flow percent of predicted value (PEF%pred), maximal mid-expiratory flow percent of predicted value (MMEF%pred), maximal expiratory flow at 25%, 50%, 75% of vital capacity remaining percent of predicted value (MEF 25%pred, MEF 50%pred, MEF 75%pred)], FeNO, and peripheral blood eosinophil (Eos) counts were analyzed. The logistic regression model was used to analyze whether airway mucus plug was a risk factor for asthma exacerbation, and the corresponding intervention strategies were explored. Results:Among the 100 patients with asthma, 24 cases were in the mucus plug group and 76 cases were in the non-mucus plug group. The distribution of mucus plug was more common in the lower lungs (30.53% and 9.16% in the lower and upper lobe of left lung, respectively; 29.01%, 14.50% and 16.80% in the lower, middle and upper lobe of right lung, respectively). The average score of mucus plug was (4.42±3.12) points. The body mass index (BMI), the number of visits to a doctor due to asthma exacerbations, FeNO, peripheral blood Eos counts in the mucus plug group were higher than those in the non-mucus plug group [(24.95±4.34) vs (23.22±2.91) kg/m 2, 0(0, 1) vs 0(0, 0), 97(37, 169) vs 31(18, 59) ppb (1 ppb=1×10 -9), 0.41(0.15, 0.70) vs 0.18(0.09, 0.37)×10 9/L](all P<0.05), and FVC%pred, FEV 1%pred, FEV 1/FVC, PEF%pred, MEF 50%pred, MEF 25%pred, MMEF%pred, MEF 75%pred were lower than those in the non-mucus plug group [(87.49±19.32)% vs (97.34±14.24)%, (76.49±19.58)% vs (91.07±18.33)%, (72.44±10.91)% vs (79.48±8.13)%, (82.36±24.46)% vs (93.83±18.27)%, (53.03±24.81)% vs (75.75±27.15)%, (46.47±22.92)% vs (64.09±25.90)%, (50.28±23.73)% vs (74.53±26.80)%, (71.30±27.55)% vs (89.92±26.82)%] (all P<0.05). In the group with mucus plug, the airway mucus plug score was positively correlated with the patient′s body weight and the number of peripheral blood Eos counts at enrollment ( r=0.413, 0.478; all P<0.05), and negatively correlated with FVC%pred and FEV 1%pred ( r=-0.576, -0.465; all P<0.05). Logistic regression analysis showed that airway mucus plug score was a risk factor for acute asthma attack ( OR=1.269, 95% CI: 1.031-1.562; P=0.024). Conclusions:Asthma patients have a high incidence of airway mucus plug, which is related to the level of Eos inflammation and body size. Airway mucus plugs can promote airflow obstruction and acute exacerbation of asthma. In clinical practice, appropriate asthma management policies can be formulated for airway mucus plugs to delay the progression of asthma and reduce the number of acute attacks.