Shanghai had only 1.17 million registered children aged 14 or younger in 2009.
If the trend continues, Shanghai's population will get significantly older and the labour pool will become proportionately smaller, the Shanghai Population and Family Planning Commission said.
The average life span of the local population is now 81.73 years. There were 3.16 million people aged 60 or above, accounting for 22.5 percent of the city's registered population.
This percentage will grow to 28.1 in 2015, 34.1 in 2020 and 38 in 2030, the commission said, according to the Shanghai Daily.
In contrast, the proportion of children is "seriously low", a trend that bodes ill for the future labour force and the boom city's growth.
By 2015, Shanghai is expected to have 21.4 million residents, including migrants. The figure will grow to 22.5 million by 2020.
Similar projections about imbalances in China's population have been made by other institutions. A seminar held by a top advisory body said by 2059, each retiree will be supported by fewer than two taxpayers.