The purpose of this study was to examine the mediation effect of peer attachment on the relationship between children`s depression and mother attachment. The respondents in this study were 697 school aged children attending elementary schools in Daegu and Gyeongbuk Province. Questionnaires, which required self-reporting by children, were used to investigate mother attachment, peer attachment and depression. The collected data were analyzed by Structural Equation Modeling(SEM) and Sobel test using AMOS 8.0, and SPSS 15.0. The results of the study were as follows. Structural Equation Modeling(SEM) revealed that peer attachment partially mediated the relationship between mother attachment and depression. First, mother attachment had a direct effect on peer attachment. Second, peer attachment had a direct effect on depression. Third, mother attachment had an indirect effect on depression as a mediated effect of peer attachment.