International financial market has been experiencing the severest turbulence since the 1930s. The US subprime mortgage crisis spread over to credit market and finally evolved into a crisis of the entire financial system of the US in 2008. Moreover，recent bankrupts of Leman Brother and other big financial giants raised a concern about the government’s role in dealing with financial crisis. In 2008，other developments，including the American economic recession，synchronized economic slowdown elsewhere，reversion of inflation expectation，tendency of loosing monetary policy in the developed economies，global credit crunch，search for short-term money market products，decreasing risk premium and crash of stock markets worldwide，cast a shadow on the international financial market.