The mild improvement follows a string of stimulus measures from Beijing, including six interest rate cuts in the year up to November as well as reductions in the amount of cash banks must keep in reserve, both intended to boost lending.
The figures come as a survey showed another slight increase in new home prices last month, suggesting the government's monetary loosening is kicking in.
However, it was short of the 49.8 forecast in a poll of economists by Bloomberg News. Anything below 50 is considered shrinkage and anything above is seen as growth.
"Although the PMI slightly rebounded this month, it still lies below the critical point and is lower than historic levels over the same period," said Zhao Qinghe, senior statistician with the National Bureau of Statistic, in a statement on the bureau's official website.
Many analysts believe the actual increase was even lower, due to factors such as the weak PMI readings.
Economists say indexes such as the PMI for December indicate that though the government is likely to achieve its 2015 growth target of "about seven percent", the economy nevertheless remains plagued by "substantial downside risks".
"The improvement in the index suggests growth momentum has continued to stabilise, in part due to the government's stimulus efforts," Fielding Chen, an economist at Bloomberg Intelligence, told Bloomberg News, adding:
The economy -- a key driver of global expansion -- grew at its slowest pace for 24 years in 2014 and has eased further this year, raising concerns on global markets.
And in July-September the country logged its worst economic performance since the global financial crisis, with growth of just 6.9 per cent.
