The purchasing managers' index (PMI) for China's manufacturing sector came in at 49.2 in October, down from 50.1 in September, data from the National Bureau of Statistics showed Monday.
A reading above 50 indicates expansion, while a reading below reflects contraction.
Sporadic and scattered COVID-19 outbreaks weighed on the October reading, the bureau's senior statistician Zhao Qinghe said.
Another cause for the decline is a contraction in energy-intensive industries, with the sub-reading at 48.8, down from 50.6 in September, according to Zhao.
The sub-index for large enterprises remained in the expansion zone at 50.1 in October, down from 51.1 the previous month. The sub-reading for production and new orders came in at 49.6 and 48.1, respectively.
Firms anticipate manufacturing activities to pick up in the near term, with the sub-index for production and business expectations at 52.6.
Monday's data also showed the PMI for China's non-manufacturing sector came in at 48.7 in October, down from 50.6 in September.