Objective: The purpose of this study is to examine the mediating effect of teacher-child emotional, verbal, and behavioral interactions on the relationship between teacher playfulness and children s peer abilities. Methods: The research method used the questionnaire method to collect data on 420 children aged 3-5 years old, targeting 108 homeroom teachers working at early childhood education institutions located in Seoul and Gyeonggi area. The collected data was analyzed using the IBM SPSS 23.0 statistical program and the PROCESS macro of Hayes (2013). Results: This study confirmed that teachers verbal, emotional, and physical interactions are closely related to young children s peer competence. In addition, it was confirmed that the teacher s playability is an important variable that affects not only the emotional, verbal, and physical interactions between the teacher and the infant, but also the peer competence of young children. Conclusion/Implications: The results of this study have significance as basic data that suggests that it is necessary to improve the playability of teachers and increase the quality level of the multifaceted aspects of teacher-infant interaction in order to support young children s peer competence.