The survey results showed that children with mental retardation accounted for 2% of the children tested in the year. Mental retardation refers to children who are significantly behind in one or more aspects of development compared to their peers, usually by 4 to 6 months. Early detection of mental retardation and early intervention are essential for the future healthy growth of the child. Generally speaking, if an infant or toddler within 3 years of age has one or more of the following abnormalities, it is highly suggestive of mental retardation: 1. abnormal crying, i.e., the time from stimulation to crying is long, sometimes repeated stimulation or continuous stimulation is needed to cause crying, or crying is sharp, or crying is small and weak; some children do not cry and seem unusually “well-behaved “2. Poor sucking ability, late chewing, easy swallowing disorder and vomiting when eating solid food; 3. Too much sleep and not easy to wake up; 4. 100 days old infants can’t hold their heads upright or have difficulty turning their heads, and one or both eyes are continuously turned inward or outward; 5. The expression of smiling only after 100 days old, and the expression is sluggish, and can’t show a natural smile by 6 months old; 6. After half a year old 7. Slow response to external stimuli, unable to look at slowly moving objects above the face at 6 months, unable to turn the head in the direction of the sound, unable to roll over on their own, unable to sit still without adult help; 8. Motor development such as prone head raising, sitting, standing, walking, etc. is 3 months or more behind normal children; and walking is unstable; 11.