Huang Guohua, a customs agency economist, said the December rise was an "important turning point".
"We can say that China's export enterprises have completely emerged from their all-time low in exports," Huang said.
The December data broke a long string of contracted export figures stretching back to late 2008.
China's politically sensitive trade surplus shrank by 34.2 per cent in 2009 to $196.07 billion, Xinhua said.
That reflected China's stronger economic growth, driven by a $586bn stimulus package, and demand for imported raw materials and consumer goods at a time when demand in the US and other foreign markets was weaker.
China's official title of world's biggest exporter is expected to be confirmed when Germany releases full-year trade figures on February 9.
Experts have said a resurgence in Chinese trade will likely bring renewed pressure on China to let its yuan currency appreciate.
The value of the yuan, which has effectively been pegged to the US dollar since mid-2008, has been an issue of contention between Beijing and its Western trading partners, who say it keeps the currency low to boost exports.
Wen Jiabao, China's premier, said last month in an interview with state media that China would not yield to foreign pressure on the yuan.