Retarded brain syndrome is mainly characterized by mental retardation. The child may have the following medical history: parents are consanguineous; mother’s pregnancy age is under 16 years or over 40 years; mother has hypertension, diabetes, thyroid disease; mother has a history of viral infection in early pregnancy; mother has a history of habitual abortion, pre-eclampsia, gestational hypertension, excessive amniotic fluid; the birth process is premature, emergency delivery, induction of labor, caesarean section of the child; after birth, there is a history of neonatal asphyxia, hypoxia, nuclear Jaundice and other medical history. Children with this disease are abnormally quiet, less crying or hyperactive and crying for 1 to 3 months after birth, unresponsive to their mothers at 4 months, not smiling at 6 months, not sitting at 12 months, and not walking and talking at 18 months. The child often opens his mouth, stretches out his tongue, salivates, grinds his teeth, often shows unconscious expressions, movements, screams or cries, his eyes are inattentive, he cannot look at things consciously, his concentration is poor, he responds poorly to things around him, his language is significantly behind that of his peers, and he has motor, visual and hearing impairments. The child has a small or large head or hydrocephalus. The disease should be detected at 16-20 weeks of gestation with amniotic fluid for chromosomal and biochemical examination to detect the cause of mental retardation in a timely manner, and if necessary, the pregnancy can be terminated. Early diagnosis and early treatment of treatable diseases should be pursued to reduce the impact on intelligence. Children with prematurity, asphyxia, hypoxia and nuclear jaundice should be actively rescued. Patiently and carefully strengthen language and motor training to enable children to take care of themselves and engage in simple labor. Cerebral developmental delay syndrome is the largest group of diseases that cause disability, and once it leads to serious damage to brain tissue, it is extremely difficult to treat, so early prevention is extremely important. It is important to do not to marry close relatives; not to get pregnant at too old or too young age; to have family history of mental illness or one of the male or female is brain retardation syndrome, as far as possible, birth control; for pregnant women to do prenatal examination and pregnancy health care, prevention of infection, as appropriate, to deal with chronic diseases; to prevent various adverse factors that may affect brain development before, during and after delivery.