Abstract: Objective: To explore the typical CT features of diffuse pulmonary lymphangiomatosis in children and improve the diagnostic accuracy. Methods: The radiologic data of 13 children with diffuse pulmonary lymphangiomatosis confirmed by clinical, imaging and pathological biopsy were reviewed retrospectively, including 6 girls and 7 boys, with an average age of 5.8 years. All the 13 cases underwent CT plain scan and enhanced examination. Results: The characteristic CT findings of diffuse pulmonary lymphangiomatosis in this group were as follows: (1) Mediastinum and hilum, peribronchovascular, interlobular septa were involved; (2) The thickening of soft tissue in mediastinum continued with the thickening of soft tissue around hilum and bronchovascular; (3) The soft tissue density in the mediastinum was low, no enhancement was observed under contrast, and there was no compression or shift in the brachiocephalic great vessels; (4) Hilar thickening, smooth thickening of soft tissue around bronchovascular and interlobular septa, most of which involved both sides of the lung, and a few involved one side at the same time; (5) Pleural thickening or pleural effusion; (6) Spleen involvement is common; (7) Cervical and or axillary lymph node enlargement and density reduction; (8) The density of several or single vertebrae wasreduced. Laboratory examination with thrombocytopenia and/or DIC was considered Kaposiform lymphangiomatosis. Conclusion: CT findings of diffuse pulmonary lymphangioma lymphangiomatosis in children show high specificity, when combined with the age of onset and clinical laboratory examinations, can significantly improve the diagnostic coincidence rate of the disease.