Students' presentation is a research-based in-class activity to present views, supporting details or research results on a given topic. Undoubtedly, teachers play important roles in presentations and teachers' roles are quite different from students' roles in this activity due to the different role expectations between them. However, in most cases, neither teachers nor students are very clear about the differences between teachers' role expectations and students' role expectations, which results in problems such as misunderstandings, low efficiency, information asymmetry, etc. This article intends to explore these differences by conducting a questionnaire survey. The research was carried out among 60 postgraduates who major in English and 10 teachers from a normal university. Research results show great differences between teachers' and students' role expectations and suggestions for narrowing the gaps are also addressed in the paper.