The General Administration of Customs said exports were up 34.4% in August compared to the same month a year ago, slowing from July's 38.1% rise. Imports jumped 35.2%, faster than the 22.7% increase in July.
China's trade surplus dropped to $20 billion in August from an 18-month high of $28.7 billion in the previous month.
In the January to August period, exports increased 35.5% from the same period a year ago, while imports rose 45.5%. A cumulative trade surplus of $103.9 billion was registered.
The strong export growth is likely to intensify calls for a stronger yuan from China's trading partners, who have accused Beijing of keeping the yuan artificially weak to make its products cheaper overseas. But the Chinese government has so far rebuffed international pressure, with authorities insisting the value of yuan will be kept stable for the time being.
U.S. lawmakers have been pressing the government to act decisively on the exchange rate issue and proposed imposing duties on Chinese goods to offset the impact of the undervalued currency. U.S. Treasury Secratary Tim Geithner is to testify at a key House hearing next week on new ways to press Beijing over its currency controls.
The U.S. July trade balance improved to a $42.8 billion deficit from a $49.8 billion deficit in June. The trade deficit with China dropped slightly to $25.9 billion from $26.2 billion in the prior month.
China has already dethroned Germany to become the world's largest exporter, with Germany's export revenue of $1.12 trillion in 2009 falling short of China's $1.20 trillion revenue for the same period.