Abstract: Objective To analyze the clinical features,etiology,pulmonary function,chest CT scans,diagnosis and prognosis of bronchiolitis obliterans(BO) in children. Methods We retrospectively analyzed 17 children with BO in Jiaxing Second Hospital,including their age,gender,etiology,clinical manifestations,changes in lung function,changes in imaging,treatment and outcome. Results All BO cases(10 boys and 7 girls)occurred following lower respiratory tract infection and adenovirus,measles virus and mycoplasma were major pathogens.The lung function test demonstrated that moderate obstructive ventilatory dysfunction happened in 4 cases,and a negative response to the bronchodilator reversibility testing.High-resolution computerized tomography(HRCT)showed mosaic perfusion in a11 cases,lung consolidation in 5 cases,atelectasis in 3 cases,bronchiectasis in 2 cases and bronchial wall thickening in 1 case.All cases received systemic and inhaled corticosteroid treatment and were provided with strengthened lung physiotherapy,a suitable nutrition,and enhanced overall growth and followed up for 3 to 27 months.And 13 cases received chest CT scan and demonstrated that no change was found in 6 cases,2 cases were progressed while 5 cases were improved,and no single case was completely absorbed. Conclusion Low respiratory infection is the most common cause of pediatric BO and adenovirus,measles virus and mycoplasma are major pathogens.The lung function test cannot provide enough early diagnostic value for BO.Classical"mosaic perfusion"with pulmonary HRCT imaging is important for early diagnosis and follow-up of BO.Systemic and inhaled corticosteroid treatment may relieve clinical symptoms,The key to the prognosis of BO is the early diagnosis,early intervention and the overall development of children.