Abstract: ［Abstract］Objective　To evaluate the effect of case-based learning （CBL） in the course of lemology science teaching，and to construct the teaching case library．Method　A total of 246 clinical undergraduates of medical faculty of Kunming Medical University were selected and randomly divided into CBL group（120）and lecture based learning（LBL）group（126）in the course of lemology science teaching. The educational differences of the two teaching methods were compared in several aspects. The teaching effect was evaluated by the results of the theoretical exames and questionnaires．Result　The theoretical test results show that the average scores of the CBL group was significantly higher than that in the LBL group（P＜0.05）．The survey results show that students' interest in the case-based learning mothod was significantly higher than that in the control group．Conclusion　The case-based learning method can stimulate students' enthusiasm，initiative，and improve the comprehensive ability to analyze problems and clinical thinking ability. Both subjective and objective indicators indicate that CBL teaching method can improve significantly the effectiveness and quality of teaching.