From BCA Research:

In an unusual disclosure, Chinese Premier Wen Jiabao publicly expressed his concerns about the safety of China's holdings of U.S. assets, putting the country's massive yet largely furtive foreign exchange assets into the spotlight. Our research finds that China currently has about 64% of its foreign reserves in U.S. assets, a level that has declined gradually from as high as 84% in 2003.

The majority of Chinese holdings of U.S. assets are risk free and long-term in nature, but there has been a clear trend in China's reserve holdings that shows a persistent increase in exposure to risky assets and non-U.S. assets...

Read full article (excellent charts accompany analysis)...

Why China should lie about its dollar holdings