A Chinese economic expert says Beijing's increasing purchases of American treasury debt is conducive to the security of China's foreign exchange investment.

Ba Shusong is with the Development Research Center under China's State Council, the country's cabinet.

"Amid the current global financial turbulence, we have to make investments in areas which are safe. Security is the top priority. Comparatively speaking, US treasuries are safer than those of other countries even though we are seeing a sinking US economy. By buying more US treasuries, China can support the US financial system and, at the same time, ensure investment security."

Ba Shusong also says that China's large holding of US treasuries will give China an edge in negotiating better bond returns.

China has become the largest foreign holder of US treasuries, replacing Japan.

As of the end of September, it held 585 billion dollars worth of treasuries, while Japan holds 573 billion dollars.