Social media could facilitate users to communicate and share the information with other people. Instagram is one of the popular social media to communicate with others by sharing a photos, videos or direct message. This popularity of Instagram can make it a potential media to develop English skills. English language skill is the ability to communicate to understand and produce the information delivered in English. This research focuses on examining the roles of Instagram and students’ activities in using Instagram to develop their English language skills. This research applied descriptive qualitative to investigate roles of Instagram in developing students’ English language skills and students’ activities in using Instagram to develop their English skills. The data was collected by interviewing four students of a Private University from batch 2015. The English Language Education Department students of batch 2015 had the most experience in developing English language skills. The findings of this research include four advantages of Instagram to develop students' English skills. The advantages of Instagram are to develop students’ listening skill, speaking skill, reading skill, and writing skill. Furthermore, this research found five activities in using Instagram that can develop students' English skills. These activities were included joining online quizzes; watching English videos; reading English captions; writing English captions; making English video or Instastory, and commenting posts on Instagram