The purpose of this study was to examine how young children s peer interaction differs according to their temperament which is perceived by teacher. For the purpose, following research questions were established; 1. Is there any difference of young children s peer interaction according to their temperament perceived by teacher? 1-1. Is there any difference of young children s positive peer interaction according to their temperament perceived by teacher? 1-2. Is there any difference of young children s dependent peer interaction according to their temperament perceived by teacher? 1-3. Is there any difference of young children s negative peer interaction according to their temperament perceived by teacher? The subjects for this study were 30 five-year-old children. Based on the results of this questionnaire, children were divided into easy, difficult, and moderate child groups. Among them, 17 of easy child group and 13 of difficult child groupwere finally chosen as the subjects. Results of this study were as follows: First, young children s peer interaction showed a significant difference between easy and difficult child groups which were perceived by teacher (p<.001). Second, young children s positive peer interaction also showed a significant difference between easy and difficult child groups which were perceived by teacher (p<.001). Third, a significant difference of young children s dependent peer interaction was found between easy and difficult child groups which were perceived by teacher (p<.001). Fourth, a significant difference of young children s negative peer interaction was also found between easy and difficult child groups which were perceived by teacher (p<.05).