Objectives: This study examined the mediated moderation effect of father's and mother's playfulness, and the child's playfulness, on the child's emotion regulation level, through father's and mother's empathic emotional reaction. Methods: Participants included 300 mothers and 288 fathers of children aged 5-6 years. They completed questionnaires that included scales to assess their child's emotional regulation and playfulness, and their own empathic emotional reaction and playfulness. Data were analyzed using structural equation modeling. Results: The relationship of father's and mother's playfulness with the child's emotional regulation level was mediated by the child's playfulness. Additionally, father's empathic emotional reaction level moderated the relationship between father's and the child's playfulness. Further, father's empathic emotional reaction level had a mediated moderation effect from father's playfulness to the child's emotional regulation, through the child's playfulness. Conclusions:These results indicate the importance of father's empathic emotional reaction and the child's playfulness. Implications of these findings for parent counseling and parent education are discussed.