Compared to studies of ethnic identity development in adolescence, fewer investigations have examined the development of ethnic identity during middle childhood, a developmental period of dynamic social and cognitive changes that have direct implications for social identity and group membership. Moreover, research on the developmental processes of Asian American youth has also primarily utilized cross-group comparisons, while neglecting consideration of variations in acculturation, socioeconomic status, and other sociodemographic characteristics within Asian American ethnic groups. Using a socioeconomically- and acculturatively-diverse sample of Chinese immigrant families in the United States (N = 169; 49.1% girls; M = 9.16 years; SD = 1.05), the present study examined how parents' ERS practices varied by parents' socioeconomic status, education, and cultural orientations, then tested associations between parents' ERS and children's self-reported ethnic centrality and ethnic regard. More highly-educated Chinese American immigrant parents reported more frequent cultural socialization and more acculturated parents reported more preparation of their children for racial and ethnic bias. Consistent with hypotheses, parents' cultural socialization was positively associated with children's self-reported ethnic centrality and positive regard. Results highlight the roles of social status and acculturation in Chinese immigrant parents' ERS, and point to middle childhood as a key developmental window for ethnic identity socialization and development in immigrant families.