The purpose of this study was to investigate students' knowledge, attitude and behavior about sexuality between the city and country side of Junior high school. Knowledge, attitude and behavior scales were used as the investigating tool. The results show as follows: There was a higher level sexual knowledge of city school students、 female students、internalcontrol of students and the students with higher level educational parents. More conservative attitude and behavior in first grade students,but the female students have conservative attitude and open mind behavior. The variables that impact on the levels of attitude and behavior were the students who have read the play boy magazines and marital states of parents. We suggest that family should have good relation ships to each other,schools develop more sex related classes,to improve students more correct sexual cognition and minimize pre-marital sexual behavior.