This study is to make clear the meaning of school discipline in Korean general high schools. The main characteristic of school discipline in general high schools is ‘separation students from outside world.’ General high schools try to reduce chances of students to contact with outside world by the rules of clothing and school timetables on which students should be in school for more than 15 hours a day. Agencies, such as schools, teachers, and students actively use school discipline for their needs, although the external form of school discipline is very similar to that of military. General high schools perform school discipline to select students who are willing to study. Classroom teachers who charge in management of students try to change school rules to make good relationship with their students and control students' behaviors. Students also actively accept school discipline to enter universities. School discipline in general high schools is closely related to competition to make social capital, which is called by Bourdieu. To be a member of a general high school that can help students to enter so-called “the first class universities” means to make a social network with ruling power and to be a member of that network. The fact that school discipline in general high schools has not changed for several decades and still works means that social network produced by school is still very important in Korean hierarchic social relationship.