Brad Setser has provided a wealth of detail in one of his latest posts called "Just what is in China's portfolio?"...some key items:
-"China has roughly $100b in U.S. mortgage backed securities"
-"China holds $600b in Treasuries...$350b of Treasuries and $250b of agencies is, well, $600b."
The Chinese government is essentially fairly exposed to the issues with mortgage lending that are now coming to light and causing problems in the financial markets, in my view.