The purpose of this study was to investigate the relations between children's playfulness and children's temperament and children's self-regulation. The subject consisted of 197 five-years-old children. Data were analyzed by Pearson's r and multiple regression analysis. The results of this study were as follows: First, there were positive relations between children's temperament and children's playfulness. Second, there were positive relations between children's self-regulation and children's playfulness. Third, children's temperament is reliable predictor of playfulness of young children. Fourth, children's self-regulation is reliable predictor of playfulness of young children.