"Research Findings:" Playfulness is an important personality tendency with an important role in the well-being, mental health, and various other aspects of an individual's life. Previous studies have shown that the development of children's playfulness is related to parents' playfulness. However, limited research has been conducted on how parental playfulness influences children's playfulness. The present study used a mixed-methods design to examine the impact of parents' playfulness on their children's playfulness and explore the mechanism of the impacting process. Questionnaires were administered to participants, who comprised 360 parents of preschool children, to test the relationship between parental and children's playfulness and explore the roles of parenting styles and parent-child relationships as the quantitative element of the study. The qualitative element comprised semi-structured interviews with 10 parents selected from the quantitative part. The results suggest that there was significant positive correlation between parental and children's playfulness and democratic parenting and intimate parent-child relationships had a chain mediating effect on this relationship. Further, parents' attitudes toward playfulness, constraints on children's play, and parental support for children in play were also the factors that influence the relationship between parental and children's playfulness. "Practice or Policy:" These findings provide approaches of interventions aimed at cultivating a higher level of playfulness, and simultaneously promoting the overall development of children.