Adolescence is a period of growth and bloom that occurs dynamically and rapidly both physically, psychologically, intellectually, socially. sexual behavior that is associated with the onset of puberty. Health problems in adolescence are one of the important problems in the life cycle. One of the adolescent health problems today is sexual activity before marriage. Premarital sexual behavior is an adolescent health problem that needs attention because this behavior risks in causing unwanted pregnancy, and various diseases such as STIs, or even HIV / AIDS. This study was conducted to determine the factors that influence the behavior of premarital sexual relations of young men in Indonesia by using Indonesian Health Demographic Survey (IDHS) data in 2017. Respondents in this study were unmarried young men aged 15-24 years numbered 12,523 people. The analysis showed that 1,258 young men had sexual relations before marriage (10.0%). There is a relationship between age (0,000), residence (0.005), knowledge (0,000) and attitude (0,000) towards premarital sexual behavior. Knowledge is one of the factors that can underlie a person's attitudes and behavior. It is hoped that adolescents will be given comprehensive reproductive health education to minimize the occurrence of premarital sexual behavior.