Power of the dollar to be tested, dollar based reserves may not be enough for China

China Finds $3 Trillion May Not Make It Comfortable In the World Economic Matrix

True, trillions of dollars under the central bank's care are thought to be invested in safe liquid securities, including Treasury bonds. The U.S. measure of China's holdings of Treasuries, the benchmark liquid investment in dollars, stood at $1.25 trillion in October, according to the U.S. Treasury Department, which cautions that the figures may not reflect the true ownership of securities held in a custodial account in a third country.

In China, like some other countries, the exact composition of China's reserves is a state secret. But analysts worry the currency armory may not be as strong as it looks. That's because some of the investments may not be liquid or easy to sell. Others may have suffered losses that haven't been accounted for.  

In addition, some Chinese reserves may have already been committed to fund pet government projects like the Silk Road fund to build roads, ports and railroad across Asia or tens of billions in government-backed loans to countries such as Venezuela, much of which is repaid through oil shipments.

Then there are other liabilities that China needs to cover, such as the nation's foreign currency debt to finance and manage imports denominated in overseas currencies. When those factors are taken into account, some $2.8 trillion in reserves may already be spoken for just to cover its liabilities, according to Hao Hong, chief China strategist at Bocom International Holdings Co.

"Considering China's foreign debt, trade and exchange rate management, it needs around $3 trillion in foreign exchange reserves to be comfortable." he said.

Ref:
http://www.bloomberg.com/news/articles/2016-01-08/china-finds-3-trillion-just-doesn-t-pack-the-punch-it-used-to

Also see:
List of countries by foreign-exchange reserves
https://en.wikipedia.org/wiki/List_of_countries_by_foreign-exchange_reserves