The purpose of the thesis is to explore the characteristics of the system of medical professions and its changes in terms of the conflicts existing among medical professions in South Korea since the 1990s, in the light mainly of Abbott’s theory of the professional system (Abbott, 1988). Four cases of conflict were examined and analysed: the conflict between oriental medicine and pharmacy over preparing oriental medicines; the one between western medicine and pharmacy over the separation system; the one between western medicine and oriental medicine over unification; and the one among the three medical professions over the National Health Insurance. Through the four medical conflicts, more complex causes and situations have been uncovered in the medical professional system and health care in Korea. The conflicts have developed from professional jurisdictional ones into economic and political ones.  Applying Abbott’s factors to the Korean cases, the following points are outstanding: salient organisational development of individual professions; inconsistency between the influence of a dominant profession and the actual result of conflict; more dynamic and fundamental influences of political, economic, social and cultural factors; and the influence of the government’s management. In the Korean cases, the main fields where claiming sole jurisdiction and conflict occurred were the public arena and the legal arena. The four Korean cases also show how actively all the actors concerned participated in the conflicts. Through the conflicts, all the players not only the professional involved but also civic groups and others learned how to react and manage situations and to develop their own organisations and strategies. This study used primary data from interviewing members, particularly elites, of the three medical professions, the government, the press and civic groups. The data included active and dynamic inside information about individual medial professions and conflicts. In-depth interviewing as a way of research can enrich the methodology of public policy in South Korea. The study is expected to give the government a macro and systematic perspective to consider the whole situation when they design a medical professional policy.