Most scholars who study the transition from authoritarian regimes to democratic ones use an actor-oriented approach, and assume four major actors participate in the negotiated transition. They explain the results of such transitions by analyzing the strategic interactions of these four major actors. If the configuration of actors and their interactions differ from one case to another, then those differences need to be explained. The case of South Korean democratization differs from democratization in other countries in two major respects. First, without significant division within the regime, the opposition bloc can manage to make a transition to democracy by maintaining coordination between the social movements and the moderate opposition party. Second, the U.S. played an important role in the process of negotiation. The negotiated transition model offers no account for the participation of a third party, and it fails to cast light on the participation of the U.S. in the Korean democratization process. This shortcoming can be solved by complementing the negotiated transition model with the mediation model in which the role of a third party can be addressed. Owing to U.S. mediation, the dynamics of negotiated transition changed in the Korean transition to democracy. / Master of Arts