The congenital cystic adenomatoid malformation [C.C.A.M.] of the lung is a rare lesion consisted of multiple cysts in the pulmonary parenchyma lined cuboidal or columnar epithelium. The C.C.A.M. presents clinically in three ways:[1] stillborn or perinatal death, [2] progressive respiratory distress in the newborn, and [3] acute and chronic pulmonary nfections in the older infant and child. We recently experienced two cases of C.C.A.M. of the lung, and have good surgical results. The first case was 29 days old male and the second case was 16 month old female who have been suffered from severe respiratory difficulty and pulmonary infection repeatedly each other. The lobectomies were performed, and the postoperative course was uneventful.