Objective: The purpose of this study was to analyze the effects of infant temperament on adaptation at childcare centers and the moderated effects of teacher-infant relationships between a vertical transition group and horizontal transition group. Methods: The subjects of the study were 284 infants, aged 1-years-old and 2-years-old, who were hospitalized in childcare centers. To investigate the correlation between variables, Pearson correlation analysis was used. Regression analysis was performed to check the effects of temperament and teacher-infant relationship on childcare adaptation. Results: Infant temperament influenced childcare adaptation in both vertical and horizontal transition groups. The quality of teacher-infant relationships was found to moderate the relationship between infant temperament and childcare adaptation in both groups. Conclusion/Implications: The results of this study, which showed different moderating effects of the teacher-infant relationship in the vertical transfer group and the horizontal transfer group, suggest the need for more diverse studies on the various transition experiences regarding childcare transition.