The purpose of this study was to examine the mediating effects of ego resilience and academic stress on the relationship between mother attachment and child‘s school adaptation. The study sample was 1,157 elementary school fifth graders (594 boys and 563 girls) who participated in the 12th wave of the Panel Study on Korean Children(PSKC). The data were analyzed with SPSS 27.0 using Pearson’s correlation and regression analysis. The results are as follows. First, children’s school adaptation was positively and significantly correlated with mother attachment and ego resilience-child. Second, children’s school adaptation was negatively and significantly correlated with academic stress. Third, ego resilience was partially mediated by the relationship between mother attachment and school adaptation. Fourth, academic stress was partially mediated by the relationship between mother attachment and school adaptation. These findings can serve as an important contribution to future research and practices for facilitating children’s school adaptation.