This study investigated the use of discourse markers (DMs) by college learners of English in China. It compared the use of DMs for four discourse functions by students at different proficiency levels. An audio–video instrument called Video Oral Communication Instrument was conducted to elicit ratable speech samples. Fraser's (1999) taxonomy was adopted to identify DMs. Quantitative and qualitative analyses indicated that while both intermediate and advanced students showed certain sensitivity to different task functions in DM use, advanced students resorted to DMs not only to construct hierarchical structures of meanings for more transactional tasks, but also to fulfill more interactive purposes for the more interactional task. Intermediate students tended to use DMs, sometimes in a confusing way, to organize their spoken discourse sequentially at minor discourse divisions, regardless of task functions. The findings overall suggest that proficiency level relates to the way DMs are used across contextual variations.