Background: The high incidence of cyberbullying behavior in social media becomes a problem that should be solved. The cyberbullying behavior among adolescent is influence by the high usage of social media, lack of emphaty, and one own's experience of being bullied. Such behavior has a lasting negative impact upon the victims of cyberbullying, especially psychologically. Research Objective: This study aims to explore cyberbullying behavior among adolescent in Yogyakarta. Methodelogy: this research was a qualitative research with phenomenology approach. Informant of this study consisted three high school students and two junior high school students that was selected with purposive sampling method. The data were extracted with in-depth interview guidline and observation through a social media platform Instagram. Data validity was performed with triangulation method and peer debriefing. The software used to perform data analysis was Open Code 4.03. Hasil: The types of cyberbullying done on instagram among adolescent in Yogyakarta such as providing rude comments, updating instastory, uploading photos, and commenting on photos. It is influenced by several factors such as the intensity of social media usage, lack of emphaty, and character of victim. Victims who experience cyberbullying will respond to the prepetrators, and the character of the victim. Victims who experience cyberbullying will respond to the prepetrator and have an impact on the lives of cyberbullying victims. Kesimpulan: the types of cyberbullying that is performed on instagram among adolescent in Yogyakarta consisted acts like rude comments, instastory updates, photo's upload and photo's commentary. Suggestions for researchers can further intervene through health promotion in social media related cyberbullying behavior so that there is no increase in cyberbullying actions in social media.