Purpose Existing studies reflect that traditional teaching–learning relationships between supervisors and graduate students have become disjointed with actuality seriously. In particular, there are practical difficulties in handling many students from coursework-based postgraduate degrees under current university curricula. Therefore, this study aims to explore the relationship between research supervisors and graduate students on social media, which is popular among students. Design/methodology/approach This study surveyed 109 graduate students from two majors (population around 100 each) of a university in Hong Kong to explore their information usage for research on social media, related attitudes and their perceived supervisor relationships. The differences between the two majors were also compared. Findings The authors’ findings indicated that graduate students were active on social media, and social media has successfully provided effective alternate ways for students to communicate with their research supervisors. Social media could improve relationships between supervisors and research students and among fellow students. Besides education purposes, students also discussed their personal affairs on social media with supervisors, demonstrating enhanced trusted relationships. Graduate students also showed confidence in the further application of social media in higher education. Some differences between respondents from the two programs were also found in terms of communication contents, strengths, personal preferences and purposes for using social media. Originality/value Scant studies focus on the relationship between supervisors and graduate students under the current social media environment, especially for students from coursework-based postgraduate degrees. At a deeper level, for the widespread use of social media in the information age, this study explores the specific changes brought about by social media. Therefore, this study is of great theoretical and practical value to graduate education under the current social media environment.