In this chapter, the author analyzes English-medium instruction lectures recorded at a medical school at a university in southern China. Using systemic functional linguistics as the theoretical framework, he focuses on the textual structure and the packaging of information in these medical lectures. The author looks at the choices of themes and thematic progression patterns as well as multimodal devices employed by the teachers to help organize the lectures and make it easier for students to follow the flow of the discourse. An approach to analyzing theme in text is thematic progression, which is concerned with the relationship between particular theme choices and preceding themes and rhemes. Three main types of thematic progression are generally identified: constant progression, linear progression, and derived progression. The author focuses on two lectures, about 50 minutes each, one entitled "Allosteric regulation of enzymes" and the other "Forensic toxicological analysis". He examines a detailed discourse analysis of the lectures from a systemic functional perspective.