Fetal central nervous system anomalies are common congenital birth defects and important contents in prenatal examination and consultation. The paper introduced the prenatal ultrasound examinations of CNS，including the planes，techniques，methods and structures for first-trimester screening，second-trimester screening and targeted examinations. The anomalies were divided into three categories according to the overall prognosis of CNS：lethal anomalies，non-lethal anomalies，and soft markers or minor anomalies. Information on prenatal diagnosis strategies，associated abnormalities，genetic evaluation and prognosis of common CNS anomalies were elaborated，including exencephaly-anencephaly sequence，alobar holoprosencephaly，Dandy Walker malformation，agenesis of the corpus callosum，arachnoid cyst，choroid plexus cyst and mild ventriculomegaly.