Purpose: The purpose of this study is to find a strategy for reintroducing the core-selective clinical clerkship system to the Seoul National University College of Medicine s clerkship curriculum, which has an unsuccessful history with this system ( 86- 90). Methods: Authors conducted a literature review to identify problems recognized from the past experience and a focus group interview with related personnel to prioritize the problems. From 5 domains of problems identified, interviewees focused on 2 problems- problems in the definition of ‘what are the core (compulsory) and the selective (optional) rotations and the tendency of students to crowd in popular subjects. Therefore, to redetermine what is core clerkship subjects and to predict the selection tendency of students, we conducted questionnaire surveys from students (N=171), residents (N=84), and practitioners (N=78). As for should-be core clerkship rotations, students and residents included radiology and neurology and practitioners included emergency medicine, radiology and orthopedics. We concluded that these 4 rotations should be added to the predetermined 5 core rotations (internal medicine, general surgery, pediatrics, obstetrics & gynecology, and psychiatrics). Students selection ratio varied from very high (69%) to very low (32%), and selected rotations by individual students showed statistically significant correlations. The students were classified, according to rotation selection tendency, into 4 clusters. Results: As for should-be core clerkship rotations, students and residents included radiology and neurology and practitioners included emergency medicine, radiology and orthopedics. We concluded that these 4 rotations should be added to the predetermined 5 core rotations (internal medicine, general surgery, pediatrics, obstetrics & gynecology, and psychiatrics). Students selection ratio varied from very high (69%) to very low (32%), and selected rotations by individual students showed statistically significant correlations. The students were classified, according to rotation selection tendency, into 4 clusters. Conclusion: Integrating the analysis of the selection ratio and that of selection tendency of individual students, we built a scenario that could prevent the crowding of students in popular specialty clerkships, and at the same time, could avoid neglecting students right to select rotations that interest them.