The behavior in children can be classified on the behavior of normal and abnormal behavior. The child's behavior can be considered normal if the behavior is in accordance with those in the community. Author conducted field research to answer the question: 1) how bullying behavior in class V students Miftahul Ulum Islamic elementary schools Sukosongo Kembangbahu Lamongan?, how the mentality of fifth grade students who received bullying behavior ?, how to influence bullying behavior towards the mentality?. Data collected through the reading and study of texts, teachers, students, documents, and others which are then analyzed by statistical analysis the percentage of engineering and product moment. The study concluded that bullying behavior in the fifth grade students of Government Elementary School Miftahul Ulum Sukosongo Kembangbahu Lamongan District of belonging to the moderate level of anxiety with a value of 53.37% mentality fifth grade students who received bullying behavior in Miftahul Ulum Islamic elementary Schools Sukosongo Kembangbahu Lamongan District of Academic Year 2015/2016 classified as moderate with a value of 53.80% and bullying behavior has a very high influence on the mentality of fifth grade students who received bullying behavior in Miftahul Ulum Islamic elementary schools Sukosongo Kembangbahu Lamongan. In line with the above conclusions, the teachers and parents are always paying attention, direction and describing the motivation to children so that they do not commit acts of bullying behavior. Keywords: bullying, mentality of students.