Objective To know the prevalence and distribution of mental retardation for children in Hainan province,and to provide scientific basis for the government to carry out the rehabilitation policy and build more rehabilitation institutions for children. Methods Selecting 37 862 children aged 0~6 years old from 18 different cities and counties in Hainan province,using the "child development issues warning signs" questionnaire screening,then the children who were positive after screening were diagnosed by clinical specialist with Gesell Development Diagnosis Scale (GDDS) and Infants-Junior Middle School Students' Social Life Ability Scale. Results In Hainan province, the prevalence rate of mental retardation was 6.1‰.The prevalence rate of mental retardation was not significantly difference among gender (χ²=4.57,P=0.032) and area (χ²=8.46,P=0.037);there was significantly different (χ²=211.81,P=0.000) among the prevalence of mental retardation of children in age;the prevalence rate of mental retardation of children with mild illness was higher than that of children with moderate and severe mental retardation in Hainan province. Conclusion sThe prevalence rate of mental retardation in Hainan province is significantly lower than the average level,which mainly is still mild mental retardation.