Abstract: Objective To discuss the behavioral risk factors of middle and high school students and pro vide reference for devising measurses of prevention and control.Methods Questionnaire survey was carried out in 1 853 students with stratified random sampling method.Results 54.5% of the students regarded without disease and with normal body function as health,among which the students of grade 1 injunior high school showed a higher ratio(67.1%)than that of grade 2 and grade 3 in senior high school(46.9% and 44.5% respectively,P<0.05).Smoking rate among boys surveyed was 9.63% and higher than that of girls.52.6% of smokers thought they smoked mainly due to the influence of the society,family and circumstance.10.6% of boys drank frequently,so as 3.3% of girls.3.13% of students in high grades had premarital sex and 0.9% in middle school students(P<0.05).Middle school students lacked of knowledge on health,especially on knowledge of healthy sex.Conclusion Several behavioral risk factors exist among middle and high school students in the city of Liuzhou,related education and inter vention should be brought via school,family and society.