[영문]This study examined the extent to which adult children perceived current and former, legal or cohabiting, partners of biological parents as family members and parents and determined what factors were associated with these perceptions. Data come from 443 adult children participating in the 1997 wave of the Longitudinal Study of Generations. Hypotheses were developed on the basis of a synthesis of the solidarity-conflict model and the life course perspective. Results revealed diversity in adult children’s perceptions of family membership and parentage and support for the theoretical perspectives. Structural, associational, and normative solidarity were all associated with adult children’s perceptions of current and former stepparents as family members and parents. Substantive and theoretical implications are discussed