Background: Adolescence is inseparable from the physical, psychological, and social changes that are affected by the environment. These changes often cause a variety of problems in adolescents, so that adolescents need the right coping mechanism to solve problems encountered. Premarital Sexual Behavior is one of the impacts arising from inappropriate coping mechanisms. Premarital sexual behavior in adolescents is influenced by several things one of them coping mechanism. Objective: Knowing the relationship between coping mechanism in adolescent with premarital sexual behavior at vocational high school 1 Girimulyo. Research Method: The design of this study used a cross-sectional approach. Methods of data collection using simple random sampling with the number of respondents as much as 50 people. The instrument used in this study is a questionnaire. The correlation test used to determine the role of parents with sexual behavior is Spearman Rank Test. Result Method: Result of research with Spearman Rank Test result obtained 0.506 result (p >0,005) meaning that there is no significant relation between coping mechanism in adolescent with premarital sexual behavior at vocational high school 1 Girimulyo. Conclusion: There is no relation between coping mechanism in adolescent with premarital sexual behavior at vocational high school 1 Girimulyo