Using a longitudinal sample of 508 Chinese preschool children, this study examined how family socioeconomic status (SES) was related to preschool children’s social skills development through family processes using multilevel latent growth curve modeling. After controlling for the effects of personal characteristics, a significant indirect effect of family SES on initial levels of children’s social skills and growth was observed and mediated through maternal depressive symptoms, marital relationships, and parenting practices. Maternal depressive symptoms from family SES was linked to poorer marital relationships and parenting practices, which were linked to children’s social skills. Authoritative parenting was related to increased growth in children’s social skills. In addition, authoritative parenting mediated the effects of marital relationship quality on both initial levels and growth in social skills. Implications for future research and intervention are discussed.