Background: The survey result ofSDKI (Basic Survey of Indonesian Demography and Health) in 2012 on KRR (Adolescents' reproductive health) shows that approximately 9.3% or 3.7 million adolescents have had sexual intercourse, while the result of SKRRI (Survey of Adolescents' Reproductive Health) shows that approximately 7% or 3 million adolescents have had sexual intercourse. One of the environmental factors on adolescents' reproductive behavior is the family factor. Adolescents who have had premarital sexual intercourse mostly come from broken homes, which has many conflicts and problems. Aim: The study investigates the correlation between parents and children relationship and adolescents' sexual behavior at Bantul. Method: The study used a cross-sectional approach and analytical correlation. The total sampling technique was used to draw 81 respondents as the samples. The data were analyzed using Chi-square statistical test. Result: The chi-square statistical test result showed that 34 respondents had a good relationship with their parents (42), and 16 respondents had a lack of relationship with their parents. Forty-seven respondents (58%) showed negative sexual behavior. P-value was 0.015 (p<0,05), meaning a correlation between parents' close relationship and adolescents' sexual behavior at senior high school in Bantul. Conclusion: There is a correlation between parents and children relationship and adolescents' sexual behavior at senior highs schools in Bantul. Adolescents and parents should be more open to each other in discussing their problems, especially their reproductive health because it is one of the ways to build a good relationship between parents and adolescents