Objective: The purpose of this study was to examine the effect of early childhood teacher-led child-centered group play therapy on young children’s sociability. The changes of sociability in the therapeutic process were also examined. Methods: The subjects of this study were 12 young children who were five years old and attended a child care center in Gangwon-do. Subjects were divided into an experimental group and a control group. The experimental group received 15 early childhood teacher-led child-centered group play therapy sessions twice a week. The sociability scale was used for pre-post tests and the data were analyzed using SPSS 23.0. Every session was video-taped and recorded verbatim. Qualitative data were analyzed to examine changes in sociability. Results: Children who participated in the early childhood teacher-led child-centered group play therapy demonstrated significant improvement in sociability. During the therapy sessions, children s expressions and behaviors associated with sociability gradually increased. Conclusion/Implications: This study supports the use of early childhood teacher- led child-centered group play therapy as an effective intervention strategy for young children to improve their sociability.