Background: School bullying and victimization are major social problems affecting students in all world. Aim Determine factors influence bullying among secondary school students in sohag city. Subjects and methods: A descriptive cross-sectional research design was used in the study. It was conducted in 4 randomly selected secondary schools. Sample was 1073 students. Three tools were used: Tool(1)Self - administered questionnaire included two parts; Part 1: Socioeconomic scale. Part 2: included questions to assess students' knowledge about bullying and factors influence it in secondary school. Tool(2) Aggression scale, Tool(3)Multidimensional peer – victimization scale. Results: common factors influenced and significantly associated with bullying occurrence in sohag secondary schools such as: age 18 years or above ,female gender, technical education , living with one parent , low socio-economic class. Verbal victimization was the higher prevalent victimization type ,anger and physical aggression were the most common aggression types among students. Boy's mechanical school found to be the most common school exposed to high level of victimization . Conclusion : Bullying was more common among female students, age equal or more than 18 years, technical education , came from low social class and lived with one parents. Recommendations: Establishing health education program about the bullying