The congenital cystic adenomatoid malformation of the lung is an unusual pulmonary entity, and usually symptomatic in infancy with sign of respiratory distress. This abnormality consists of enlarged, multicystic lobe with smooth-walled cysts of variable sizes, which can communicate with major bronchi through malformed air passage that usually lacks in cartilage. Roentgenographic findings are three types. First type is multicystic pattern showing various sizes of cysts and causing mediastinal shift with pulmomary herniation. Second type is dominant cystic pattern underlying multicystic lesion. Third type is solid homogenous mass. Prompt surgical resection is choice of treatment. We recently experienced a case of congenital cystic adenomatoid malformation of the lung of 27 day female in fant and report with review of literatures.