Because of the purpose, pertinence and timeliness of the case-based teaching method, it has been more and more applied in the class teaching in universities. In the Microbiology teaching, teachers can pull in abundant materials as cases according to the teaching arrangements, such as classical experiments, social hot pots, histories of science and so on. By the cases carefully selected before the class and effective guidance in the class, teachers can train the abilities of students to find, realize and solve problems and develop their active scientific thinking. Meanwhile, teachers should try to avoid the case teaching to be just a form.