Objective: The teaching effectiveness was evaluated following CBL teaching reform in internal environment system to provide reliable reference for improving teaching mode and teaching quality. Methods: The questionnaire survey was conducted in 190 clinic students of 8-year program and 60 clinic students of 5-year program to investigate the teaching effectiveness following implementation of the teaching reform called “classroom sectional study of patient case debate competition seminare .The contents of questionnaire survey included: the student’s view on characteristics and advantages of this reform program and the reason for favoring and supporting the reform. Investigation was conducted using an anonymous questionnaire. Data collection and analysis were performed by using Excel and PSS17.0 statistical software

percentage of each observing parameter was calculated. Results: ① The student’s view on advantages of this reform program included as following: reducing student study burden by 78.5%，increasing the students' engagement in class activities by 85.4%

improving teaching quality in class discussion by 80.5%

enhancing team spirit among students by 78.5%

expanding students' thinking and exploring space by84.3%

and similarity of this teaching mode to clinical diagnosis and treatment process reached to 84.0%. ② The student’s reasons for favoring and supporting this reform program included: reducing student study burden by 83.4%

improving teaching quality in class discussion by 72.4%

and training student’s ability to search clinical information by 82.4%. Conclusion: This CBL reform program reduced student study burden

improved teaching quality and favored by students

therefore providing a positive valuable reference to other discussion class.