Abstract
Adolescence is a period where an individual develops from the first time showing his secondary sexual signs until he reaches sexual maturity (Monk, et al. 2002). The tendency of adolescents in unhealthy behavior such as premarital sex will affect their reproductive health status. Several factors such as knowledge, lack of functions of the role of family, sources of information about reproductive health, and affordability of health care centers affect their reproductive health behavior. This study uses an explanatory mix method research design, which combines qualitative and quantitative methods involving 384 second grade students. Measurements made in this study are knowledge, attitudes, and information sources, using a modified IDHS questionnaire. The results of the bivariate analysis using the Chi Square test showed that there was a significant relationship for attitude factors with premarital sexual behavior (p-Value = 0.000 <?), there was no significant relationship for the Knowledge factor (p-Value = 0.142 <?) and information source factor (p-Value = 0.443 <?) with premarital sexual behavior in adolescents. The study concludes that the attitudes / views of adolescents on maintaining reproductive health related to premarital sex is associated with their sexual premarital behavior.