The Chinese manufacturing PMI declined to 49.7 in August from 50.0 in July, in line with expectations, according to the Chinese government. It was the lowest level since August 2012.
A reading above the 50 mark indicates expansion, a reading below 50 indicates contraction.
"There is insufficient growth momentum in the country's manufacturing sector," Zhao Qinghe, an economist at the National Bureau of Statistics, said.
The services PMI fell to 53.4 in August from 53.9 in July.