Chinese exports have tumbled 8.3 per cent in July, their biggest drop in four months and far worse than expected, reinforcing expectations that Beijing will be forced to roll out more stimulus to support the economy.

Imports also fell heavily, suggesting domestic demand might be too feeble to offset the weaker global demand for China's exports.

Economists had forecast exports to fall just 1 per cent, after a 2.8 per cent uptick in June, but the data showed depressed demand from Europe and the first drop in exports to the United States, China's biggest market, since March.

Exports to the European Union fell 12.3 per cent in July while those to the US dropped 1.3 per cent. Demand from Japan, another big trading partner, slid 13 per cent.

"A recovery in external demand remains far off and economic growth will continue to rely on domestic demand, which implies policies should continue to be relaxed in the second half," Qu Hongbin, China economist at HSBC, wrote.