This research is designed to provide policy suggestions for the Republic of Korea in responding to China’s newly launched Asia Infrastructure Investment Bank(AIIB) in 2015. The AIIB may be an embryo to contend alternatives of existing U.S. led global monetary rules. That is why the U.S. and the West doubt if the AIIB would contribute to the development of global monetary system. They concern if China arbitrarily manipulate the AIIB for its own national benefits, such as utilization of the Belt and Road Initiative in Asia. However, according to international regime theory, once an international regime established, it tends to be independent from the big power that initiated it. So, the AIIB also can not be simply managed by Beijing if the other member countries wisely cooperate one another. In addition, Seoul can utilize the AIIB to contribute to the Asian economic development and even the Korean Peninsula’s stability by helping and contributing to the AIIB. Meanwhile, China and the U.S. need each other to cooperate for their common national interests despite their superficial conflicts. In 2015 China-Korean summit in Beijing acknowledged that Korea’s Eurasia Initiative, and China’s Belt and Road Initiative are complementary, and decided to cooperate each other. Both countries’ cooperation in the AIIB also encourages the Belt and Rode and the Eurasia Initiatives.