China's official purchasing managers index (PMI), a measure of activity in the sector, came in at 50.8 last month, Xinhua news agency quoted the National Bureau of Statistics as saying.
The figure was lower than the 51.1 recorded in September and compared with the preliminary 50.4 figure in a private survey released by British bank HSBC on October 23.
PMI tracks activity in China's factories and workshops and is a closely-watched indicator of the health of the economy.
HSBC is scheduled to release its final PMI reading for October on Monday.
The Chinese economy expanded 7.3 per cent in the third quarter, lower than the 7.5 per cent expansion in the previous three months and the slowest since the depths of the 2008-2009 global financial crisis, the government announced last month.
Beijing's 2014 growth target is about 7.5 per cent, the same as last year, though officials including Premier Li Keqiang have openly stated a slightly slower increase is tolerable as long as the job market remains resilient.
A slowdown in China's huge property sector is also weighing on overall growth, with economists worrying that a potential destructive bust in housing prices could dent economic hopes for the Asian powerhouse, a key driver of global and regional growth.
