This case study has reported the corpus-based materials development research and argued that the Corpus-Based materials developing stages deserved more attention in the whole process of teaching and learning. The empirical research was conducted with four teachers and 180 third-year medical students. The participants' comments regarding the functions of corpus-based supplementary materials and activities as a supplement in learning the ESP language skills were analyzed and juxtaposed with the observation data for participants. The significance of this study are multi-aspects: Enriching medical teaching materials; promoting participants' teaching and learning efficiency, quality, and enhancing the relationship between teachers and students; as well as diversifying the Medical English pedagogy. Results indicated that a well-arranged, concise, and convenient Corpus-Based English Supplement (ECBES) is very useful for both teachers and students. They had benefitted from the pedagogical implications of using the ECBES in-class and in their daily learning life.