In most rural areas, a couple may have a second child after a break of several years.
China has 130 million elderly residents, who make up just over 10% of the population.
This is as a result of the strict one-child policy, introduced in 1979 in an attempt to control China's booming population. Under the law each couple living in the cities is allowed only one child, unless one or both partners are from an ethnic minority or they are both only children.
In most rural areas, a couple may have a second child after a break of several years.
The law is particularly strict in cities, where forced sterilisations, late abortions and punishment of couples who break the rules have often triggered international criticism.
But the policy has badly backfired, leaving the working population struggling to provide for those who have retired.
Resentment
A growing number of single young people are finding themselves faced with the daunting prospect of caring for parents and four grandparents - a phenomenon known as a 4-2-1 family.
But this does not change the fact that with the communist welfare system fast disintegrating under the pressure of economic reforms, many people are finding it increasingly hard to provide care for their elders.
Those that can afford it have begun to transfer their traditional responsibilities of looking after their relatives at home to private nursing homes - a move which has itself sparked some resentment.
Elderly people in China were traditionally venerated and today's elderly population expects to be looked after. Some people have even sued their families for neglect.
By the year 2030 officials estimate that care for an estimated 300 million elderly will consume a full 10% of national income.
Unless further action is taken, experts say the burden of caring for a greying population could begin to have a major impact on the speed of China's development.