Purpose: This study was conducted to look at the relationship among sexual consciousness, reproductive health knowledge and sexual experience. Method: the subjects were 276 high school students in 4 high schools in Gyonggi Province and Chungnam Province. The data was collected from August 1 to September 10, 2003. Result: The average age of the subjects is 16.5 years old, composed of male students, 154 persons(55.8%), and female students, 122 persons(44.2%). The mean scores of sexual consciousness, reproductive health knowledge and the mean level of sexual experience are 28.9, 10.5, and 1.7 respectively. There is a significant difference in sexual consciousness and sexual experience by sex (t=-3.22, p<.001; t=8.17, p<.001), the male students have more sexual experience than the female students, while the girls have a higher sexual consciousness than boys. Sexual consciousness has a negative relationship with reproductive health knowledge and sexual experiences(r=-0.13, p=0.04;r=-0.17, p=0.01). Sexual experience has a positive relationship to reproductive health knowledge(r=0.21, p<.001). Conclusion: We can conclude that sexual consciousness and reproductive health knowledge are weakly related to sexual experience. In addition we suggest developing an educational program to enhance sexual consciousness for high school students considering sexual differences.