This study analyzed the mediating effects of co-parenting in between parent-child interaction and school readiness, and confirmed the importance of parent-child interaction and co-parenting as based on the results. Korean Child Panel 7 (2014) used data from a child living with parents. Pearson's correlation and a three-step regression analysis of Baron and Kenny (1986) were conducted. The results of this study showed that parent-child interaction, co-parenting, and readiness were positively correlated with significance level of .01 in all and all sub-domains. Co-parenting mediated the between parent-child interaction and school readiness. In detail, among the sub-scale of school readiness, learning attitude, cognition and common knowledge were partly mediated, and social emotion development and communication were mediated completely. Based on the results, some ways were discussed the development and implementation of a parent education program including role play, parent counseling, and the provision of a support system that includes couples counseling for parenting