The purpose of this study was to explore the differentiation of common personality profiles and defense mechanisms between medicine and surgery specialist groups. The authors evaluated the defense mechanisms of the specialist by using Ewha Defense Mechanisms Test. The authors compared the defense mechanisms between two groups (medicine and surgery specialist groups) who are employed Soonchunhyang university hospital at 2000. First, There were significant differences in mean scores of the defense mechanisms ratings. For the surgery groups, projection and show-off were significantly higher than in the medicine group, and for the medicine groups, altruism was significantly higher than surgery groups. Second, Compared of maturity level between two groups, the medicine group used mature defense significantly. Third, We compared of major defense mechanisms between two groups. Surgery groups used show-off as a major defense mechanisms in significantly higher frequency than the medicine groups. This results were reflect that surgery group have property of apprentice system and dramatical therapeutic approach. The results seem to be useful in understanding specialist s optimal character for specific specialities that were selected by evaluating the differences of the common characteristics and coping mechanisms of each specialty group.