Bullying is a behavior which is coercion or attemp to harm physically, verbally or psychologically by someone to a weaker person. Bullying action occurs in there major cities in Indonesia namely Yogyakarta, Surabaya and Jakarta. Bullying incidence in Yogyakarta reached 77,5%. For the level violence that occured at the junior level reached 66,1%. The most effective bullying handling is the teacher because the teacher is the key agent of change in the handling of bullying. Departing from the importance of the occurrence of bullying in the world of education, then held research. Problems of this research (1) how knowledge and attitude of junior high school teacher to bullying? (2) how to prevent bullying in SMP Negeri 11 Yogyakarta? Purpose : to know the description of knowledge and attitude of junior high school teachers to bullying in SMP Negeri 11 Yogyakarta. Methode : This research is a non-experimental research that is descriptive survey with a sample of 21 respondents with total sampling technique using questionnaires about knowledge and attitude toward bullying. Result : The result of research on teacher’s knowledge and attitude toward bullying in SMP N 11 Yogyakarta with good category 18 respondents (85,7%) and enough category there are three respondents (14,3%) (2) teacher attitude toward bullying with good category reached 17 respondent (81,0%) and enough category there are four respondents (19,0%). Conclution : Knowledge and attitudes of teachers to bullying in SMP Negeri 11 Yogyakarta achieved good and sufficient category. Suggestion : For futher research it is hoped that the research will not only spread the questionnaire but can be done by interview.