According to Market News International and others, the People's Daily has indicated that:
"About 70 pct of China's reserves are held in US dollars, confirming widespread speculation about the weighting."
That was rather obvious the moment the US released its survey data showing that China held around $525b in US securities at the end of June 2005. A 70% ratio now implies that China probably has around $700b in US securities. That is real money — as is the roughly $150-200b in US securities China has to buy every year to keep its dollar holdings at 70% of its (rapidly growing) reserves.
Any one care to guess how large an impact that has on US interest rates? (My estimates are in my testimony)
China's new (marginal) transparency probably isn't good news for professional Chinese reserve watchers though. The mystery is gone.
But China's disclosure does throw into question (I think) the work of all China analysts who use don't adjust for valuation and still use reserve growth to derive estimates of hot money flows. With $300b or so in non-dollar reserves, 2-3% moves in the euro/dollar or pound/ dollar and the like can generate substantial monthly variation in China's headline reserve total.