尽管一国货币的升值是其经济发展的必然结果，但来自外部的压力不可忽视。很多时候，来自霸权国家的货币升值压力可以左右一国政府的政策选择。20世纪80年代中期以“广场协议”为标志的日元升值与美国施加压力有很大关系，2005年7月21日以来的人民币升值同样承受了美国的压力。美国为什么要施压他国货币升值？美国为什么能够施压他国货币升值？处于美国压力下的日本政府和中国政府又该如何应对呢？带着这些疑问，本文分析了日元升值和人民币升值中的美国因素。本文共分三部分具体展开。第一部分主要论述了战后日本汇率制度的演变及日元的升值过程、新中国成立后汇率制度的演变及人民币的升值过程、战后美元霸权的建立与美国汇率政策的演变和汇率的国际政治经济属性。并根据美国在日元升值和人民币升值过程中是否施加压力、施加压力的大小，选取第三阶段的日元升值和目前人民币升值作为比较对象。第二部分先重点论述了日元升值和人民币升值过程中的美国因素，再从产业竞争关系、市场开放程度、外汇储备规模、全球化程度的高低、国家间的政治经济关系、日中政府对本国货币升值的态度这六个角度分析了日元升值过程和人民币升值过程中美国因素的差异。第三部分先重点论述了日元升值和人民币升值过程中日本政府和中国政府的应对，接着从日中两国的外贸依存度、高新技术产业情况、金融系统的完善程度、社会保障和社会稳定程度的高低、国际政治地位的高低、与美国关系的紧密程度、对本国汇率改革控制能力的大小，分析了处于美国压力下的日本政府和中国政府的政策选择差异。

Although the appreciation of the currency is one of the inevitable results of domestic economy development, the pressure from outside can not be ignored. The pressure from the hegemony in one nation’s currency appreciation can influence the government’s policy decision. In the mid-1980s, the appreciation of the Yen, with the mark of the "Plaza Accord", is under the heavy pressure of the United States. Now, the appreciation of RMB is facing the same pressure from the U.S.A. Why does the United States government force other country to appreciate their currency ？How can the United States government put pressure on other nations’ currency appreciation？How do the Japanese government and the Chinese government respond under the pressure? With these questions, the dissertation analyzes the U.S. influential factors in the appreciation of Japanese Yen and the RMB. This dissertation is composed of three parts. Part 1 focuses on the evolution of Japan's exchange rate regime after the world war two and the process of the appreciation of the Yen, the evolution of the China's exchange rate regime and the process of the appreciation of the RMB after the founding of the People's Republic of China, the establishment of the hegemony of the U.S. dollar and the evolution of the United States’ exchange rate policies, and the international political and economic attribute of the exchange rate. In accordance with whether the United States’ putting pressure on the Japanese Yen's appreciation and the RMB's appreciation or not , and the degree of it's pressure, this study compares the current appreciation of RMB with Japanese Yen’s appreciation in the 3rd stage.Part 2 focuses on the U.S. influential factors on the appreciation of the Yen and RMB first. Then the study analyzes the differences on policy decision between Japanese government and Chinese government by the industrial competitiveness, the degree of market opening, the scale of foreign exchange reserves, the level of globalization, the political and economic relations between countries, and the attitude on currency appreciation of Japanese government and Chinese government.In Part 3, the study discusses the Japanese government's response to Yen’s appreciation and the Chinese Government's response to RMB’s appreciation, and analyzes the policy making differences between the government of Japan and China under the U.S. pressure from the perspectives of Japan’s and China’s dependence on foreign trade, hi-tech industries, financial system, social insurance and stableness, international political status, relationship with the U.S. and their control on civil exchange rate reform.