Purpose:to review an allergic bronchopulmonary aspergillosis case Method: reviewing the CT images of an allergic bronchopulmonary aspergillosis case and comparing the images of different processes Result:High-resolution computed tomography(HRCT)of the chest showed some dilatate bronchi were filled in linear opacities throughout both the lung fields,especially severe in inferior lobe.The CT value of the opacities was about 60HU without obvious enhancement.After 15-day anti inflammatory drug treatment,the patient had a CT scan again(Fig.2).But there was no obvious changes compared with the prior imaging.The result of the third CT scan after one month showed a turn for better compared to the second examination.There were residual bronchiectasis but the mucus plug nearly couldnt be found.The forth examination was taken one month after last,the imaging showed almost no change compared with the previous time.Bronchiectasis still existed but mucus plug disappeared.Conclusion: Chest CT is a sensitive,noninvasive technique for the recognition of central bronchiectasis,it is also helpful in monitoring the course of bronchiectasis in the patient with ABPA.HRCT of the chest is the radiological investigation of choice in patients with ABPA.The CT imaging in different course of disease is different.It can be atelectasis,transient pulmonary infiltrates,proximal bronchiectasis,and signs of mucoid impaction.The imaging of the patient we report reveals bronchiectasis and mucous plug in bronchi throughout both the lung fields.Although CB is believed to be a characteristic finding in ABPA,the significance of it as a specific diagnostic marker for ABPA is controversial for it is reported that almost 40%of the involved lobes have bronchiectasis extending to the periphery.We must make a diagnose overall consideration including the clinical manifestation,radiographic imaging,laboratory examination,and so on.