Objectives : The Purpose of this study is to apply an oral health education program to the high school students, to analyze their oral health knowledge and changes of behaviors, and to examine oral health education for effective, thus using all of those results as the basic data for developing materials on their oral health education. Methods : The study was conducted on the freshmen and women of M high student in Seoul City. They were in total 85 student, consisting of 77 of male student(90.6%) and 8 of female student(9.4%). Knowledge survey contained 38 questions including such as dental common knowledge, dental caries, and periodontal disease, while behaviors survey did 24 questions including such as tooth-brushing, brush selection and management, and prevention of oral disease. Results : First, oral health education had brought to improve oral health knowledge for high school students. Second, even with the improvement of oral health behaviors through the education, there was not statistically significant on behaviors such as the regular checkups and the usage of dental floss. And third, the students in general were satisfied with the oral health education. Conclusions : First, the oral health education being conducted in kindergarten and elementary school should be continued or expanded into the adolescence. Second, the oral health education should be focused efficiently on the learning objective demanding for a change of behavior through the repeated education, for which the education that is right for the high school students should be done. And third, for the effective oral health education in high school, the media that could cause interests should be developed.