Mental retardation (MR) is a group of disorders in which a child’s intellectual development lags behind the average level after birth or in early infancy, i.e., within the developmental period in which it occurs (up to 18 years of age), the general intellectual functioning is significantly lower than the level of his or her peers, and it is accompanied by deficits in adaptive behavior. Xiao Hua, Department of Neurological Rehabilitation, Guangzhou Women’s and Children’s Medical Center Intelligence Quotient (IQ) is 2.0 standard deviations below the mean of the population (the mean IQ of the population is set at 100, and one standard deviation of the IQ is 15), and a general IQ of 70 (or 75) or less is considered to be an intellect that is significantly lower than the average level. Adaptive behavior includes both the ability to lead a personal life and to perform social duties. Mental retardation is referred to in psychiatry as “mental retardation,” “mental retardation,” “mental retardation,” and “mental retardation. In psychiatry, mental retardation is called “mental retardation”, “mental retardation”, “mental deficiency”. In education and psychology, it is called “intellectual backwardness” and “mental deficiency”. Pediatrics refers to “mental retardation”, “mental retardation”, “mental retardation”. Special education schools refer to “mental retardation” or “intellectual disability”. Intelligence tests and behavioral assessment Intelligence tests are often used for mild MR, but for severe MR, it is often difficult to use intelligence tests, and it is necessary to rely on behavioral assessment scales, which are not as reliable as intelligence tests for identifying mild MR. Therefore, the two methods should be used in conjunction with each other, and the results must be analyzed comprehensively. Intelligence test methods 1, Wechsler Intelligence Scale for Children (WISC-CR): for children aged 6 to 16 years. 2.Chinese-Weichmann Early Childhood Intelligence Scale (CWYCSI): applicable to children aged 4 to 6 and a half. 3.Infant and Toddler Developmental Checklist (Gessell ScaleR) is applicable to children aged 0～3 years old. Adaptive Behavior Rating Method 1. Infant-Toddler-Junior High School Student Social Life Competence Scale is applicable to children from 6 months to 13 to 15 years old. This scale is an indispensable tool for diagnosing MR and grading. 2.Newborn Behavioral Neurological Assessment (NBNA) The National Association group has determined the normal range of NBNA for newborns nationwide through investigation and research, and its clinical should is being carried out gradually.