In international relations, ¡§Foreign Aid¡¨ is a perfect tool to perform the diplomatic policy of a country. In the aspect of theory discussion, the development of foreign aid theory exists the arguments about idealism and realism. The idealist estimates the foreign aid policy according to humanism and moral standards, but the realist emphasizes the key point to provide foreign aid or not according to the benefit of nation. Since 1970, in order to get the identification, support, and the authority of the third world nations, and to compress the international society existence of Taiwan, the Communist Party of China uses plenty of economic aids as the tool to pursue their diplomatic objectives. In the post cold war era, the diplomacy competition for the third world nations between Taiwan and the Communist Party of China is more violent than ever. This situation can be known by the facts that the Communist Party of China had tried to join the United Nations vigorously before 1971 and that Taiwan is also more vigorous to return to the United Nations and to join the World Health Organization. No matter to return or to join the United Nations, Taiwan and the Communist Party of China both need more affirmative votes of the third world nations in the United Nations General Assembly to achieve their objectives. So, in the diplomacy competition of both sides of strait, Taiwan and the Communist Party of China need more support of the third world nations. Relatively, both sides of strait in order to get the identification of the third world nations both use foreign aid to draw an outsider to one¡¦s side and to establish diplomatic relations. That Taiwan and the Communist Party of China both use the influences of nations with foreign relation to generate the mutually beneficial and subtle interactive relations is worth to be observed and discussed.