This study examined the mediating effects of self-esteem on the teacher-young child relationship and self-regulation ability of young children. A survey was conducted on a random sample of 252 young children aged 3-5 years attending a nursery in Gwang-ju, Korea. Based on the data, Person’s correlations between variables were analyzed, and hierarchical regression analyses were conducted to identify the direct and indirect effects of the teacher-young child relationship and self-esteem on the self-regulation ability of the young children. First, there were positive correlations among the teacher-young child relationship (intimacy) and self-esteem as well as self-regulation ability. There were negative correlations among the teacher-young child relationship (conflict, dependence) and self-esteem as well as self-regulation ability. Second, self-esteem partially mediated the correlation between the teacher-young child relationship and self-regulation ability. The results suggest that self-esteem may affect the self-regulation ability of young children as a mediating response to the teacher-young child relationship.