Though the image of South Korea and China today are vastly different, paradoxically, these two countries share numerous similarities upon a closer look. For example, both countries experienced a certain period of time in which they were ruled by authoritarian dictatorship, they also experienced rapid economic development, many social conflicts, protests, and economic and political events, such as the Reform and Opening and the Summer Olympic Games. The unique feature of this research project is to elucidate the two economically similar cases that have seemingly different political systems, and to provide a reason as to how the different results came about. This research project raises the question as to why China, a country which has achieved significant economic development has stagnated in its political development while South Korea has experienced a complete change of its political system. This dependent variable is the polarized political situation, communism and democracy, that China and South Korea have, respectively. To understand the two cases, this research project applies the optimistic structuralism of Lipset's modernization theory, and the pessimistic structuralism of Huntington's "political decay" approach to South Korea and China's case. Through the empirical studies in the China, the strong consolidation of institutional functions in the political system in China was discovered. It is a very important finding because it is how China has maintained its authoritarian regime, while South Korea ended its authoritarian regime in 1988, and moved to a democratic society. To avoid potential shock, the Chinese government is exerting more effort to decrease political corruption and provide the clear separation of power. Thus, by responding to the citizen's demands, China would be decreasing political decay and increasing its nation's stability with the institutional cooperation. Therefore, this project argues that China, a country which has achieved dramatic economic development, has failed in its political development while South Korea has been able to succeed in both economic and political development because the political institution in China have played an important role in terms of preventing people's demands to change the political system.