This study investigated the influence of mother-child communication and rejection anxiety on school-age children\'s peer attachment. The participants were 441 school-age children in Daegu or Gyeongbuk Province. The collected data were analyzed by Two-way ANOVA, and Multiple Regressions, using SPSS PC(15.0 version). The results were as follows. (1) School-age children with a lower level of mother-child communication perceived higher level of peer attachment than children with a higher level of mother-child communication. And school-age children with a higher level of rejection anxiety perceived lower level of peer attachment than children with a lower level of rejection sensitivity. (2) In addition, interaction effects of mother-child communication and rejection anxiety on peer attachment were observed. (3) The explanation power of mother-child communication on school-age peer attachment was rather higher than rejection anxiety.