PBL teaching method is a new mode of teaching which is originated from the West and implemented into China in recent years with an expectation that it would mainly develop the students’ self-learning ability, and enhance their skills of comprehensive thinking and solving actual problems. The author summarizes the practical experience of using PBL teaching methods in the theory teaching in Department of Medical Microbiology and Human Parasitology, China Medical University in the past three years, and then proved this method is very helpful to improving the students’ integrated thinking by analysis of sample .At the same time the results also suggested that the students showed high enthusiasm in discussing the cases. By this way, the students showed great subjective intiative in their studies.