The purpose of this study was to establish a better operation plan for medical school student internship by gaining a deeper understanding of the student internship process. Toward this end, an investigation was carried out using in-depth interviews of students with experience as student internship at Catholic University of Daegu School of Medicine. Students who participated in the student internship program at Catholic University of Daegu School of Medicine took part in the clinic twice every two-week period for a total of four weeks as a member of the care team. The students performed several activities during their internships, including for example history taking, physical examinations, keeping medical records, simulation of writing prescriptions, clinical skills, patient education, night work, and rounds with the attending professor. In this study were analyzed the contents of a student internship, the difference in clerkship, the competence of the faculty, student participation attitudes and the overall effect of the internship on the students. It was found that the in-depth contents, passion of members including professors and students, especially the role of the professor, was more important component than the contents of the internship program or clinical training. The student-intern system was revealed to have the following positive characteristics: 1) education deeper than clerkship was performed through one-on-one faculty-student interaction, and 2) students' experience was broadened.