China's purchasing managers' index (PMI) for the manufacturing sector dropped to 51 percent in December 2013, down from 51.4 percent in November, according to official data released on January 1.

December marked the first time since June 2013 that the manufacturing PMI had declined, according to a statement jointly released by the National Bureau of Statistics (NBS) and the China Federation of Logistics and Purchasing (CFLP). An index above 50 indicates expansion while an index below 50 indicates contraction.

Zhao Qinghe, an economist from the NBS, said that the weaker momentum indicated by December's PMI is due to seasonal factors. "The PMI figure still shows expansion in December, and it has remained above 50 for 15 consecutive months, which means the general industrial situation is stable," said Zhao.

Chen Zhongtao, an analyst from the CFLP, said that during the process of accelerating structural rebalance and controlling overcapacity, the growth rate of manufacturing industries may continue to slow in the near future.

"A key task for 2014's macroeconomic policies is to expand domestic demand in order to stabilize overall growth, and to be careful about possible sharp contractions of exports since the international environment is complicated," said Chen.

Supportive measures are also needed to help the growth of small-scale manufacturing businesses, which will strengthen entrepreneur confidence, he added.