This is a descriptive study to understand the preventive stage for STDs to provide a basis for sex education for college students. The colleges were selected by quota sampling in five representative cities in Korea, but the1,691 college students were selected by convenient sampling in the cities nationwide, and the data were collected by self-reporting using questionnaire consisting of 33 items. The results were as follows : 1. Their mean ages were 21.8 for female and 23.3 for male students, 2. 78.0% of the males and 46.5% of the females permitted premarital sex, 57.1% of male and 10.3% of female college students had experienced sexual intercourse, 7.1% of males and 2.4% of females had experienced pregnancy, 10.3% of males and 3.4% of females had been infected with STDs, 72.1% of male and 13.8% of female didn't use condoms at the time of infection. 3. Most of the factors related to STDs infection, such as drinking, smoking, frequency of sexual intercourse, pregnancy, knowledge of STDs, the score of STDs prevention were statistically higher in the male student group than in the female group. 4. The student's mean score of knowledge about STDs was similar between the male group(7.80)and the female group(7.84) with a possible score range from 0-18. 5. Only fifteen percent of male and 9.6% of female students expressed that they will do something to prevent STD. 6. The group having the experience of sexual intercourse(t=3.924, P=.048) and the group of having experience of contracting STDs(t=16.638, P=.000) had shown statistically higher STDs prevention score than the group not having that kind of experience, but the group not having experience with pregnancy didn't show any difference from the group not having experience with pregnancy. Considering that 57.1% of males and 10.3% of females had sexual intercourse experience, 78% of male and 46.5% of female permitted premarital sex, 10.3% of male and 3.4% of female had been infected with STDs. It could be concluded that the college students were ignorant about the prevention of STDs and had unrealistic stage of the STDs prevention. Therefore, enforcement of education for the prevention of STDs including the dynamics of the sexual intercourse and STDs infection is needed.