The purpose of this study is to analyze the characteristics of the South Korean democratization and nationalism in terms of the development of nationalism in its political process from the Liberation to 1987. This study is fundamentally oriented to the critics of the theoretical perspective which is to investigate the south Korean democratization in point of view of institutional change, that is, realization of democratic procedure(competitive election). In the South Korean democratization, I argue, nationalism is different from others, in that it was the political ideology strongly engaged in the action of the dominant forces, and also of the resistive ones. From the regime of Yi Seung-man to that of Chun Do-whan, despite of their apparent difference, Nation and Nationalism were, without exception, founded in ethnic, historical and cultural elements, and strongly engaged in the political conflicts around the democratization.