Imports shrank 2.6 per cent from a year earlier, customs data showed Monday.
That came on top of earlier data that showed August factory output fell to a three-year low.
Exports rose 2.7 per cent over a year ago, down sharply from double-digit growth of recent years as Europe's debt woes and a sluggish U.S. recovery hurt demand for Chinese goods.
China's economic growth fell to a three-year low of 7.6 per cent in the quarter ending in June, hurting demand for imported oil, iron ore and consumer goods.
Private sector analysts expect growth to fall further in the current quarter.