This study examined the effects of family SES on children's mathematics achievement for urban, rural, and migrant families in China. The data comprised 6050 children (44% female, 56% male) in grades 4 and 5 from a national database in China. The results showed that parental education level and family income were directly related to children's mathematics achievement. The effect of family income on parental educational expectations was significantly stronger among rural families than among migrant and urban families. Family income had a stronger effect on family learning stimulation for migrant and rural families than urban families. And, the effect of the parents' level of education on parental educational expectations and family learning stimulation were significantly stronger among urban families than among migrant and rural families. The findings suggest that group-specific services are needed, particularly for Chinese migrant and rural families. The findings are discussed in an international content.