The purpose of this study was to survey the variations of financial linkage among China and ASEAN countries in the last decade and the meaningfulness for the development of overseas Chinese merchant by using the tests of the changes in the long-run equilibrium relationships between the U.S. S&P 500 Index，the SSE Composite Index in China and the stock markets of Singapore，Malaysia，Indonesia，Thailand and Philippines in ASEAN around the Subprime Mortgage Crisis. The main findings demonstrated that there were significant increases in these long-run relationships between China market and the markets of ASEAN countries during the period of the U.S. financial crisis，and China has more influence on ASEAN stock markets. The result shows that China has become an economy leader in East Asia，presently. The suggestions on policy are such as：China should participate in the infrastructure in ASEAN countries by the framework of “The Belt and Road”，and establishes the CNT and the Red Capital Market to attract the Southeast Asian Chinese enterprise listing of their company in China by the IPO.