The purpose of this study was to investigate whether parent-child interactive play therapy would change interactions between institutionalized infants and institutional fosterers and their child-rearing attitudes. A play therapy was designed to consist of total 11 sessions including pre stage, mediating stage, and post stage. Three findings were follows: first, parent-child interactive play therapy caused positive changes to interactions between institutionalized infants and institutional fosterers. Second, parent-child interactive play therapy also brought positive changes to the child-rearing attitudes of institutional fosterers. Finally, parent-child interactive play therapy program was also proven effective as it contributed to change the quality of interactions during the sessions. Although there are some limits to generalize the findings of the study, which was a small-sized case study.