China's foreign trade growth trumped market forecasts to post double-digit rates in May, boosted by slightly improved external markets and more working days in the month.

Exports and imports totaled $343.58 billion in May, up 14.1 percent year on year, rebounding from the 2.7-percent growth in April, said the General Administration of Customs on June 10.

The figure replaced the monthly trade record set in November 2011, when foreign trade amounted to $334.11 billion.

Both imports and exports reached record highs in May, with exports climbing 15.3 percent from a year earlier to $181.14 billion, and imports rising 12.7 percent to $162.44 billion. Trade surplus hit $18.7 billion in May, slightly higher than the $18.42 billion in April.

Improved markets in the United States and Japan, stable growth in emerging economies, as well as less pressure for the yuan to rise further helped boost May's trade data, said Huo Jianguo, Director of the Chinese Academy of International Trade and Economic Cooperation.

But the country should still be cautious about the long-term trend, Huo said, citing uncertainties with the euro-zone debt crisis.