The purpose of this study was to investigate the effect of cooperative group circle game on young children's social competence.For the purpose, following research questions were established; 1. How does cooperative group circle game affect young children's social competence? Subjects for the study were 40 five-year-old children attending a kindergarten attached to K elementary school in Geojae, Gyeongnam. The instrument for young children's social competence was the Young Children's Social Competence Instrument (Woo, 2002).To test the research questions, means and standard deviations of two groups' pre- and post-tests were calculated, and then ANCOVA's were conducted to test group differences, putting pre-test scores as covariates.Results of this study were as follows: First, there was no significant group difference of young children's social competence. The activities of cooperative group circle game didn't affect young children's social competence in positive ways.Second, the significant group difference of young children's initiative was found (p < .05). The the activities of cooperative group circle game positively affected on young children's initiative.Third, the significant group difference of young children's cooperation was found (p < .05). The the activities of cooperative group circle game positively affected on young children's cooperation.Fourth, there was no significant group difference of young children's sociability. The activities of cooperative group circle game didn't affect young children's sociability in positive ways.