Abstract: Objective To study the characteristic clinical manifestations， CT manifestations， diagnosis and treatment characteristics， and analyze its relationships with prognosis of the children with pulmonary Langerhans cell histiocytosis（PLCH）. Methods In a retrospective study， the clinical features and imaging data of 17 children with PLCH were analyzed as well as the efficacy and prognosis after type Ⅲ chemotherapy of 6week induction phase and 52-week maintenance phase. Results All children suffered onset pulmonary diffuse change with multiple organ damage and in the process of disease development； most of the chest computed tomography（CT） showed characteristic changes. All the 17 children were received type Ⅲ chemotherapy， and 8 cases got complete remission with good prognosis， 4 cases relapsed after chemotherapy including 1 case with good prognosis and 3 cases of death， 3 cases abandoned treatment due to progression during chemotherapy. In addition， 1 case with progression received reinduction chemotherapy and survived with the present continuous chemotherapy. One case of maintenance chemotherapy treatment was followed-up. Conclusion Children with PLCH were infants and young children with multiple organ damage. Early intenstive chemotherapy can improve the prognosis， but some cases of lung progress are apparent.