Hot money inflow reached 1.02 billion, 4.45 billion, 5.31 billion and 12.5 billion US dollars in February, March, April and May, respectively, said the report from the international center of National Bureau of Statistics.

There is no clear definition of hot money, and the figures were calculated by deducting foreign direct investment and trade surplus from the country's foreign exchange reserve increase, a normal way of calculation in the world, the report said.

Investment from Hong Kong and other sources outside China's mainland has poured into the real estate sector, apparently hoping to profit from rising prices and an anticipated rise in the yuan, which would push up the value of mainland assets in foreign currency terms.

Such investment rose 27.9 percent in the first six months of the year, compared with the same period of 2005, the Ministry of Commerce said. This prompted the government to release on Monday proposed rules that would let foreigners face restrictions on residential property purchases, though details have yet to be hammered out.

"Effective measures should be taken to gradually quash the betting on the appreciation of renminbi ("people's money," another name for yuan)," the NBS report said.

Market-oriented reforms on China's exchange rate system should be pushed forward, it added, referring to the move China announced exactly one year ago to scrap the yuan's peg to the US dollar, while linking it to a basket of currencies, and allow the currency to float within a managed band.

The yuan has since risen about 3.5 percent, less than some daily movements of the dollar or euro.

The United States says the yuan's rise is too small, adding to complaints by some U.S. companies that the yuan is undervalued by up to 40 percent, giving China's exporters an unfair price advantage and hurting foreign rivals in the Chinese market.

But many Chinese officials and economists say China's currency reform reflects a major improvement as a new floating mechanism has been imposed on the exchange rate.

"Though there is still room for improvement of the determination mechanism for the yuan's exchange rate, it is clear that another one-off, government-ordered revaluation will not happen," the National Bureau of Statistics spokesman Zheng Jingping told the press last Tuesday.

The yuan was traded at 7.9870 to the US dollar on Tuesday.

The NBS report also includes policy proposals about "encouraging domestic firms to make more investment abroad and appropriately control overseas capital inflow."