With the rapid advance of science and technology, the ways of human communication have changed greatly. Multimodal Discourse Analysis has become a new research direction, interested in communication signals other than languages such as pictures, colors of performances and languages. The theory of Systemic Functional Linguistics by Kress and van Leeuwen (2006) leads to an important advance in discourse research associated with visual images which play a motivational role in supporting the effectiveness of teaching materials and stimulating medical students' interest to learn languages in more creative ways. This study investigates the interactive meaning of five visual images in two medical textbooks proposed by using the framework from Kress and van Leeuwen (2006) so as to strengthen the educators' capacity in constructing and interpreting multimodal texts.