Beijing says the policy, which was introduced in 1980 and is widely disliked, has helped China by slowing population growth and easing the strain on water and other limited resources. But the abrupt fall in the birth rate is pushing up average age of the population of 1.3 billion people.
Demographers have argued that this has created a looming crisis by limiting the size of the young labor pool that must support the large baby boom generation as it retires.
"It's great. Finally the Chinese government is officially acknowledging the demographic challenges it is facing," said Cai Yong, an assistant professor of sociology at the University of North Carolina at Chapel Hill.
"Although this is, relatively speaking, a small step, I think it's a positive step in the right direction and hope that this will be a transition to a more relaxed policy and eventual return of reproductive freedom to the Chinese people," Cai said.
