The rapid reserves expansion began in 2001, since then the reserves figure has maintained strong, double-digit annual growth.

In October 2006, the figure crossed the threshold of 1 trillion U.S. dollars for the first time. In less than three years, the figure had doubled by June 2009.

Guo Tianyong, a professor with the Central University of Finance and Economics, told Xinhua on Thursday that the rapid reserves growth was closely related to the country's galloping economic growth.

China's trade surplus and foreign direct investment have maintained strong momentum in past years, and the anticipation of a strengthening yuan and relatively high interest rates in China have attracted an increasing amount of international speculative capital, or hot money, leading to stronger reserves growth, according to Guo.

China's State Administration of Foreign Exchange (SAFE) announced in a report released in February that 35.5 billion U.S. dollars of hot money had flowed into the country in 2010, accounting for 7.6 percent of the increase in its foreign reserves for that year.

"Capital inflows from overseas were in accordance with the real economy's fundamental situations, despite small amounts of illegal hot money inflows," the SAFE said.

Pace to moderate as trade structure optimizes

Guo Tianyong expected the country's rapid reserves growth to slow down, as the country's trade surplus this year will narrow further after dropping for two years in a row.

China's foreign trade is steering toward a more balanced direction. Its trade surplus has dropped for two consecutive years.

Data from the General Administration of Customs (GAC) showed that China saw a trade deficit of 1.02 billion U.S. dollars from January to March this year, the first quarterly trade deficit in six years.

Zhuang Jian, a senior economist with the Asian Development Bank, echoed Guo's view, saying that the growth rate may drop with the optimization of China's foreign trade.

"Although there were some seasonal factors contributing to the trade deficit in the first quarter, we can clearly see that China is actively implementing the policy of stabilizing exports and boosting imports," said Zhuang.