Objective: The purpose of this study was to examine the sequential mediating effects of self-esteem and positive peer play interaction between warmth parenting and the social competence of preschoolers. Methods: The 7th wave of the Panel Study on Korean Children(2014) was used to analyze 1,113 preschoolers. Sequential mediation effects were analyzed using SPSS Process Macro(Hayes, 2013). Results: Warmth parenting indirectly affected preschooler s social competence(cooperation, assertion, self-control) by yielding sequential mediation effects on self-esteem and peer play interaction. Namely, warmth parenting does not directly affect social competence but does have a significant effect on preschooler self-esteem, which positively affected peer play interaction. This path increases the social competence(cooperation, assertion, self-control) of preschool children. Conclusion/Implications: In order to increase the social competence (cooperation, assertion, self-control) of preschool children, it is important for the preschooler to consider themselves a worthy person and to learn positive interaction techniques through warmth parenting.