The purpose of this study was to examine the main and interaction effects of fathers’ parenting and their play participation on emotional regulation of preschoolers. The participants of this study consisted of 269 preschoolers (M: 61.4 months, SD: 15.3) located in Seoul and Gyeong-gi province. The results of regression analysis revealed that; 1) Father's parenting (such as rational instruction, friendly attitude) positively predicted child's emotion regulations. 2) The interaction effects of fathers’ parenting (such as parenting participation, reaction, rational instruction, friendly attitude) with their constructive play participation predicted children’s emotion regulations. Namely, fathers with higher constructive play participation showed higher emotion regulations of preschoolers under father's parenting participation, reaction, rational instruction and friendly attitude. 3) The interaction effects between fathers’ functional play participation and father's parenting participation predicted children's emotion regulations. Findings indicate that fathers play a role in improving children’s emotion regulation by parenting. Moreover, its effects appeared more apparently when fathers participated with constructive and functional play methods. In conclusion, it is suggested that fathering and the level of play involvement may be key variables for developing young children's emotion regulation.