Craniocerebral CT scans were performed on 50 subjects including embryos, fetuses and newborns. Fetuses were divided into three stages based upon CT findings. The first stage ranged from the 8th gestational week to the 12th week, and the second stage from the 13th to 23rd week. Beyond 24 gestational weeks, fetuses were classified as the third stage. In the first stage, it is difficult to recognize the intracranial structure on CT scans. In the second stage, the intracranial structures on CT scans become clearer. Around the lateral ventricle a symmetrical high-density area appears, which corresponds to the germinal matrix. However, at the third stage, the high-density area disappears. The morphological changes of the ventricular system with growth are ascribed to a remarkable development of the cerebral parenchyma.