In July 1969, the Nixon Doctrine, enunciated by the U.S. President Richard Nixon, stated in relation to military defense, that ”the United States is going to encourage and has a right to expect that this problem will be increasingly handled by, and the responsibility taken by, the Asian nations themselves”. Nixon also announced that the U.S. would negotiate with the People's Republic of China (PRC) to ”normalize” U.S.-China relations. The Nixon Doctrine had a significant impact on the Republic of China (ROC) and South Korea, making the former face the crisis of losing Chinese representation at the United Nations (U.N.) and raising tensions on the Korean Peninsula for the later. Should the U.S. improve its relations with the PRC and consequently transfer Chinese representation at the UN to the PRC, North Korea's status would be secured and South Korea's status in the U.N. would be threatened. On account of this, the 1971 change of Chinese representation at the U.N. not only jeopardized both the ROC and Korea but also reshaped diplomatic relations between the two nations, leading to South Korea's establishment of ”renewed China-Korea relations”.The article focuses on the South Korean government's attitude to and stance on the issue of Chinese representation at the UN during the changing international situation in 1971 and analyzes the Korean government's change in China policy after the PRC became China's representation at the UN. Under the pressure of independent self-defense and foreign policy, the 1971 event, considered by South Korea as a major diplomatic crisis, began the change in Korea's China policy.