The liberalization of ChinaUS air market is the typical representative for the development of Chinese international aviation market policy, which also has great impact on the trend of longhaul widebody aircraft. In 2003, CAAC(Civil Aviation Administration of China) suggested to promote the open sky policy gradually, and began to take part in the trend of international air market liberalization. Since then, Chinese civil aviation started to adjust the international policy in order to support the air liberalization and international cooperation. However, the hubbuilding initiatives are still seriously changed by competing hubs in Seoul and Tokyo. Moreover, Air Service Agreement Protocols signed in 2004 and 2007 have influenced ChinaUS market deeply, the volume of passengers has increased sharply while the competition becomes fierce.