Objective To study the effect of case-based learing(referred CBL) teaching method in medical psychology and probe into the application value in teaching. Methods The students were divided into two groups. 45 students in a experimental group were instructed by using CBL teaching method while 44 students in a control group were lectured by using lecture-based learning(referred LBL) teaching method. After the end of the course the students from both groups were supposed to take the same test and complete the same questionnaire so as to evaluate the effect of CBL teaching method. Results The experimental group’s scores are higher than the control group’s scores on theory test , the difference was statistically significant (P <0.05). The experimental group was higher than the control group on the final course exam scores, but the difference was not significant (P> 0.05). The experimental group’s evaluation scores about teaching methods are higher than the control group except the item of"teacher’s teaching attitude" , the difference was statistically significant. (P <0.001). Conclusions There is a significant effect on the teaching of medical psychology using CBL teaching method. CBL teaching method is able to stimulate students' enthusiasm and initiative, help students analyze and solve problems , improve the ability of clinical thinking and practice.