The Purchasing Managers Index (PMI), an effective gauge of the manufacturing sector, came in at 53.8 percent in September, up 2.1 percentage points from August, said the China Federation of Logistics and Purchasing. Nine of the 11 sub-indexes, including production and new orders, increased in September compared with August.

The September index reading was the highest since May and marked the 19th consecutive month that the index was above 50 percent. A reading above 50 percent indicates economic expansion, while below 50 percent indicates contraction.

"The September index shows the slowdown in China's economic growth has stabilized," said Zhang Liqun, a researcher with the Development Research Center of the State Council.