This study aimed at examining the effects of child care teacher's self-efficacy, classroom environment, teacher interaction on negative peer interaction. For this study, the data of the 5th Panel Study of Korean Children(PSKC) in 2012, collected from 600 children and their teachers were used. The structural equation modeling was used for data analysis. The results revealed that lower teaching self-efficacy and inappropriate classroom environment were related to low level of sensitive and supportive teacher behavior with children. In addition, teacher-child interaction as a medium of teacher's self-efficacy and classroom environment indirectly influenced on the negative peer interaction of children. Findings suggest that teacher's self-efficacy, classroom environment and teacher-child interaction can affect peer relationships of children. This study provides evidence that quality teacher-child interaction in quality child care environments can serve as protective factors for children at risk.