BEIJING - China will maintain a low birth rate and keep the population within 1.39 billion by the end of 2015, according to the 12th Five-Year Plan on the country's population development issued by the State Council on Tuesday.

China had more than 1.34 billion people by the end of 2011. In five years, the number of people aged 60 and older will rise to more than 200 million, it said.

Meanwhile, the size of the labor force will peak during the next five years and will start dwindling slowly and steadily after that, it expected.

Until then, China will see a rise in its dependency ratio - the ratio of those outside the labor force, such as seniors and children, compared to those in it, experts said.

"For China, that indicates an increasing pressure on the productive population to support the old," said Lu Jiehua, a sociology professor at Peking University."And that might impact the nation's economic development in general," he warned.

In recent years, a labor crunch began to emerge in the country, previous reports said. According to Yuan Xin, a professor at Nankai University's population and development institute in Tianjin, 100 working people now support 40 non-workers.

Given a steady number of children, China's rising dependency ratio is prompted mainly by a sharply rising number of the old, he explained.

(For full story, please see April 11 China Daily, page 4.)

The reporter can be reached at shanjuan@chinadaily.com.cn