Congenital cystic adnomatoid malformation(CCAM) is rare pulmonary cystic disease, CCAM has been detected on prematurity, stillborn and respiratory distress infant or child by chest X-ray film and CT scan. One case of CCAM diagnosed in utero at gestational age 22 weeks is reported with sonographic findings and autopsy findings. Ultrasonographic findings are large cystic lesions in fetal thorax and fetal hydrops without hydramnios. The survival of these infants is very poor despite accurate prenatal diagnosis and maximal postnatal care.