Abstract: This paper reviews recent studies on changes in cerebral blood flow, brain structure and brain biochemical markers, and describes pathological mechanism of abnormal nervous system development among small for gestational age(SGA) infants in order to arouse physicians' attention on the intellectual development, cognition level, behavior development and other aspects of SGA after birth and to achieve the goal of early detection and early intervention, and provide evidence for improving the long-term life quality of SGA.