Drawing upon an adolescent sample (age 10-15) collected by the China Family Panel Studies (CFPS) in 2010，this paper examines the role of parental involvement in mediating the relationship between family SES ( socio-economic status ) and adolescents， educational expectation， and investigates whether the mediating role of parental involvement differs across urban and rural families in recent China. Results based on structural equation modeling shows that both the effects of parental education and family income on adolescents5 educational expectation are effectively realized through parental involvement. For urban adolescents， the two dimensions of parental involvement operationalized in this paper， parental academic expectation and parental daily care， could substantially explain the effects of parental education and family income on adolescents5 educational expectation. For rural adolescents， the effects of parental education and family income are just partly explained by parental involvement. We also propose our explanation in the conclusion part with respect to the differential mediating roles of parental involvement in urban and rural families.