The study attempts to find out how Indonesian students apply Discourse Markers (DMs) to build coherence in English compositions. It employs a descriptive design, analyzing 52 target DMs and how they are used in 21 argumentative papers. The participants of the study were 21 Master's students majoring in English Language Teaching (ELT). The results reveal that the participants employ 44 DMs in 234 occurrences, and use some DMs inappropriately in 118 occurrences. The problematic matters cover: non-equivalent exchange, overuse, surface logic, misinterpreted relation, and mistranslation. The study concludes that although the participants have shown their awareness of using DMs to build coherent compositions, there are areas where improvement is needed to increase their ability in using DMs appropriately and effectively to make their writing better and more logically connected. Recommendations to English teachers are also given as pedagogical implications of this study.