The Research of the Relationship between the U.S., China and Taiwan After the 911 Incident Abstract The traditional diplomacy of America puts its main focus on Europe with little attention on Asia, however after having the 911 Attack in the U.S.2001, Bush junior administration has immediately adjusted the pace of global strategies. The main strategy has shifted its focus towards Asia, it shows that the US makes National Defences the first priority and seeks for the support of counter- terrorism from China in Asia. Before the 911 incident, China was not at the very heart of American policy in Asia policy, as a result of 1999 Chinese Embassy bombing in Belgrade in the former Yugoslavia Republic of Serbia and the April 2001 Hainan reconnaissance plane incident, there had been an awkward tension between U.S. and China. After seeking the cooperation of counter terrorism with China, it presented an opportunity that the U.S. and China can use to improve their relationship. Since the normalisation between U.S. and China, it has been through from the ¡§strategy cooperation relations¡¨ which was established to against Russia to the neorealism of ¡§constructive relations,¡¨ Clinton era formed a ¡§comprehensive association¡¨ with mainland China and advanced it into ¡§ constructive strategy partnership,¡¨ yet, before 911 Attack, the relationship of Bush junior Administration and China were ¡§strategic competitors¡¨, then after 911 incident, due to the strategy transformation of U.S., both parties developed ¡§ Constructive cooperation relations, ¡¨ even though there are still conflicts on the benefits, U.S.-China relation has ameliorated to some extent. As far as U.S. concerns, China is regarded a partner of counter terrorism and benefit exchanger by the world, yet U.S. recognises China as a potential strategic adversary, in some ways, U.S. still exposes the threatening gesture to China. Bush junior has indicated to China that U.S. does not support the independence of Taiwan, but if China force invades Taiwan on the premise that Taiwan does not declare independence, U.S. does not rule out the possibility of assisting Taiwan by the means of miliary. It has shown the U.S. strategy has changed from ¡§strategic ambiguity¡¨ to ¡§strategic clear¡¨ since Clinton to Bush junior. After the 911 incident, the relationship of U.S. and China has definitely improved in a short period, in terms of the long run, both parties still have serious differences regarding to the problem of Taiwan, human rights, economics impacts and anti nuclear proliferation. These conflicts still restrain the development of U.S and China relationship, in addition, U.S. has troops in middle Asia, in terms of the military strategy, the benefit of Mainland China is deprived. In terms of long term U.S-China relationship, it represents a cooperative yet defensive relationship, on the basis of that Taiwan does not declare independence, according to U.S.-Taiwan relationship, U.S. will secure the safety of Taiwan, and maintain the peace cross-straits.