Recent years, the open attitude to sex has prevailed rapidly. Such trend has a great influence on the adolescents in developing stage. But, current education system is not work efficiently on this problem. So the purpose of this study is to identify the factors of adolescent sexual deviation and to propose one approach to sex education program. This study was surveyed from 1,391 adolescents in high school and juvenile reformatory from Sep. 1 1996 to Sep. 30 1996. They were samples grouped to three categories(academic high school, business high school and juvenile reformatory) and were analysed by each according to category and gender. The major findings are as follows. 1. The individual characteristics of the respondents: In the average age, they were years old, many of them were christian, they had 2.4 brothers and sisters, most of their parents were alive, and most of them answered for their economic status and school score as mid-class. 2. In family circumstances(intimacy with parents, relationship between both parents, and recognition of daily behaviors of adolescents) the index was highest in academic and lowest juvenile reformatory. 3. In school life, the juvenile reformatory students showed lower school adaptability and the higher possibility of keeping bad company. In adaptability, girls were better than boys in academic school(P<0.001). The degree of keeping bad company was higher in boys than in girls in business high school(p<0.001). But in juvenile reformatory girls(p<0.05) showed higher degree of keeping bad company more than boys. 4. Juvenile reformatory boys had experienced more sexual media(98.4 %) and delinquent behaviors(99.2%) than girls. On the contrary girls had experienced alcohol(87.7%), smoking(95.1 %), and drugs(79.0%). 5. In sexual awareness including friendship with the other sex, virginity, controlling sexual impulses, and sexual violence, juvenile reformatory student\'s score was the lowest (p<0.001). In detail by gender, boys were more often minded to friendship with the other sex than girls. Students having the other sex friends showed better awareness of friendship with the other sex and thought little of virginity. 6. Boys feel the impulse of sex more frequently than girls(p<0.001). On the contrary, surprisingly girls(93.8%) of juvenile reformatory have experienced kiss or hug. In case of intercourse, academic school boys(13.2%), business school boys(22.4%) and juvenile reformatory girls(87.7%) were reported to have experienced sexual intercourse. 7. To the question of the first time of kiss or hug, Academic high school students experienced kiss or hugs in the middle school years for the first time(boys 56.0%, girls 47.4%), business high school boys middle school years also(49.6%), business high school girls high school years(49.4%), juvenile reformatory students experienced kiss or hugs in the middle school years(boys 71.6%, girls 84.2%). Many of respondents thought kiss or hugs as love. After kiss or hugs, many of boys felt good but many of girls felt nothing. The place of kiss or hug were usually parks, video rooms or friends\' rooms. Most of their partner were their the other sex friend. 8. Academic and business high school students experienced sexual intercourse for the first time on the high school years usually, juvenile reformatory students middle school years. To the motive of intercourse, academic high school girls were forced to do that but business high school and juvenile reformatory girls because of love. Boys thought that as love too. After sexual intercourse, academic and business high school girls got worried about pregnancy, juvenile reformatory girls felt nothing, and boys felt good. They used the houses of their friends and video rooms as the place of intercourse. 9. Logistic regression analysis shows, in case of academic high school, sex, smoking, age, awareness of virginity and delinquencies were statistically significant factors for sexual behaviors. In case of business high school, alcohol, smoking, and awareness of virginity were statistically significant factors for sexual behaviors. In case of juvenile reformatory, sex, consciousness of friendship with the other sex and sexual violence were statistically significant factors for sexual behaviors.