Demographers and economists are advising Beijing to keep a close watch on population figures, with the proportion of people of working age having shrunk last year for the first time in a decade.
Although they insist there is no cause for alarm, they say the data provides further evidence that the country has lost its 'population dividend' - the notion that nations with younger populations fare better economically.
Economists cite this factor as being crucial to China's three decades of phenomenal growth that has established it as the world's second biggest economy.
The population aged between 15 and 64 - the internationally accepted range for labour forces - dropped to 74.4 per cent of the total population last year, a drop of 0.1 percentage points from 2010, the National Bureau of Statistics said.
The number of people over 60 reached 185 million, accounting for 13.7 per cent of the total and rising 0.47 percentage points. And the population above 65 hit 123 million, 9.1 per cent of the population - up 0.25 percentage points.
'Although it is still possible to see some minor fluctuations in the next few years, it is worth paying much more attention to the impact [of a decreasing] labour supply,' the statistics bureau said.
But analysts also noted that because the population had risen so quickly, the number of workers had not dropped, despite many baby boomers born six decades ago dropping out of the work force and the birth rate falling dramatically under the nation's one-child policy.