Congenital cystic adenomatoid malformation [CCAM] of the lung is extremely rare. The patient was 10 year old female and had no specipic signs and symptoms except right lower chest pain for 5 days ago before admission.On simple chest X-ray and thoracic CT scan, about 9x8x8cm sized, heterogenous marginal enhanced multiseparated hypodence lesion with air fluid level and gas bubbles in posterior pleural space in right lower chest .The culture result of needle aspiration of cavity was apergillus flavus. Right lower lobectomy was carried out and the result of biopsy was congenital cystic adenomatoid malformation.