The change to China's decades-old one-child policy is a step toward achieving a more balanced population age demographic, family planning officials and experts said.

As part of a blueprint for economic and social reforms drawn up by the Communist Party of China leadership, couples will be allowed to have two children if one of the parents is an only-child.

"The new policy will help maintain a reasonable labor force and slow the pace of population aging, thus benefiting economic growth," said Wang Pei'an, vice-minister of the National Health and Family Planning Commission, during a seminar with population experts in Beijing on Sunday.