The purpose of this study is to examine involvement of teacher with peer conflicts among infants in 0 year olds class. The subject of this study are three teachers who are in charge of 0 years old class and nine 0 year olds class infants of public child care center. The method of this research is ethnographer's method that is about the guiding principle of a teacher in charge of 0 years old class, and used a camcorder to analyze the transcribed categorization when an infant has a conflict. The results are as follows. Involvement of teacher are typed waiting calmly, speaking of an infant's thoughts, understanding of vexation, leading to play with peers, turning attention, explain, teaching.