Family changes in China are characterized by a dual rise in marital disruption and remarriage. However, the implications of these changes for child well-being remain understudied. I analyze data from the 2015 China Education Panel Survey to profile and explain well-being disparities between children in intact, disrupted and remarried families. Child well-being is poorer in disrupted than in intact families. Remarriage, particularly of both parents, is associated with further harm to children’s well-being. Mothers’ remarriage is associated with a broader range and greater extent of damage to children’s well-being than that of fathers. Neither social selection nor economic and non-pecuniary resources explain poorer child well-being in disrupted families and stepfamilies than in intact families. Household structure only explains why children in disrupted families, but not in stepfamilies, fare less well than those in intact families. Variations in child well-being with parents’ marital status are consistently explained by poor parent-child relations and parental conflict. Reflecting on the theories of selectivity, resource deprivation and structural instability, the findings highlight the need to consider China’s distinctive sociocultural and institutional settings in configuring the implications of ongoing family changes for child well-being.