Objective To explore the efficacy and safety of omalizumab in the treatment of allergic bronchopulmonary aspergillosis(ABPA).Methods The clinical data of 26 ABPA patients treated with omalizumab in Zhongshan Hospital,Fudan University from November 2018 to December 2023 and 24 ABPA patients treated with prednisone combined with itraconazole in the same period were analyzed retrospectively.The primary outcomes were exacerbation times and oral corticosteroid-sparing effect.The secondary outcomes were respiratory symptoms,circulating eosinophil count,total immunoglobin E(IgE)level,specific IgE for aspergillus,pulmonary function(the percentage value of forced expiratory volume in one second predicted[FEV1%pred]),fraction of exhaled nitric oxide(FeNO),thoracic computed tomography(CT)manifestation and adverse reactions.Results In omalizumab group,the exacerbation times of ABPA after 6 and 12 months of treatment were 0(0,0)times/6 months and 0(0,1)times/6 months,there was no significant difference(P=0.157),which were significantly lower than those of the baseline(1[1,2]times/6 months,P＜0.001).The oral dose of prednisone decreased from 10(5,15)mg/d(before treatment)to 3.125(0,5)mg/d(6 months after treatment,P＜0.001).After 12 months of treatment,the oral dose of prednisone was 0(0,3.125)mg/d,which was significantly lower than that of the baseline dose(P=0.003).After treatment with omalizumab for 12 months,the FeNO level decreased significantly(26[13,36]×10﹣9 vs 30[18,56]×10﹣9,P=0.049).There was no significant difference in blood eosinophil count,total IgE level,specific IgE for aspergillus and FEV1%pred before and after omalizumab treatment.After 6 months of treatment with omalizumab,respiratory symptoms were relieved in 23 patients(88.5%)and radiographic improvement was achieved in eight out of sixteen patients(50%)with mucus plugs.More patients successfully discontinued oral prednisone when treated with omalizumab for 12 months than those in control group(P=0.035).During the treatment of omalizumab,4(15.4%)patients had a slight increase in alanine aminotransferase(ALT),and 1 patient was complicated with hepatocellular carcinoma during follow-up.Conclusions Omazumab treatment can effectively reduce the number of acute episodes of ABPA,reduce the dosage of oral glucocorticoids,improve FeNO,facilitate the absorption of mucus plugs,and has high safety.