Nowadays, the rivalry of power between superpower countries are common and had existed in international relations. The form of that such relationship has transformed by the birth of newly developed nations, which it could become a threat to the United States as the greatest superpower these days, that newly developed country is the People's Republic of China. Unwilling to budge, the two countries are making efforts to expand its influence in various regions, such as Southeast Asia. Southeast Asia is a strategic area because it has a lot of potential advantages for them both. Thus, the war of interest between the two countries is seen through a partnership reinforced by US and China, China through Regional Comprehensive Strategic Partnership (RCEP) and the US through the Trans-Pacific Partnership (TPP). Furthermore, there is an implication to Southeast Asia as the target object of this rivalry. Being caught in the midst of the situation, Southeast Asia has a challenge to play its role.