Couples will receive at least 600 yuan (HK$564) per person per year if they have only one child or if they stop having children, even if their first two children are girls, officials told a press conference.

The approach is aimed at slowing rural population growth.

Under the new ``social support system,'' the money will be paid from the time the couples are 60 until they die.

Officials said the system is ``more humane'' as it uses rewards, rather than punishment, to encourage people to follow the country's controversial ``one-child policy.''

The two-decade-old policy makes it illegal for urban couples to have more than one child, but allows rural couples to have a second child if their first is a daughter.

Stiff fines are handed to violators, who sometimes see their property seized or relatives put in detention.

Pan Guiyu, deputy director of the State Population and Family Planning Commission, defended the policy, saying the world's most populous country is fighting an uphill battle against a swelling population.

Pan said the policy had avoided 300 million births over 30 years, the equivalent, she said, to the population of Europe.

``The good effects are very apparent,'' she said. ``But can we relax now? I should tell you, we are still facing a grave situation.''

China launched the policy in the early 1980s to curb its population, now more than 1.3 billion, but the restrictions have bolstered a traditional preference for boys. They have also come under fire from western countries and human-rights activists.

Sex-selective abortion is banned in China, but ultrasound scans have made it easier to know a baby's gender in advance, increasing the chances for aborting girls.

Chinese traditionally prefer sons because they are seen as more able to provide for the family. Government figures show 119 boys are born in China for every 100 girls.

Maniland media have speculated over a possible change to the one-child policy after several places, including the financial hub of Shanghai, loosened control of couples having a second child.

But an experiment, named ``rewards and assistance,'' has been under way in some rural areas since last year, Pan said, with cash rewards handed out to farmers who abide by the one-child policy.

Zhao Baige, vice minister in charge of the commission, said earlier this month that the one-child policy has been misunderstood in the West - that in rural areas it allows for two children and in minority communities, there are no restrictions at all.

But she also noted that the policy has caused a disparity between the male and female population.

The lack of a social-security system for China's farmers also forces couples to exceed birth quotas or abandon girls so they can have sons.

Farmers depend on sons to take care of them in old age as daughters are married off.

``With this policy, we've basically addressed this old-age support problem in the countryside,'' Pan said. ``This will greatly increase the status of girls.''

She admitted the scheme, which will cost the government 800 million yuan this year, will not be enough to change every family's mindset.

``This is a very good beginning, but it's not enough because there are many factors behind China's traditional preference for boys,'' Pan said, citing as an example families' desire for sons to carry on the family name.

It is unclear whether 1,200 yuan a year is enough of an incentive for people to have girls, but it is a sizable sum for farmers, given that average annual per-capita income in rural areas is 2,600 yuan. The project is an expansion of a pilot program, launched last year, which covers a handful of provinces and cities. This year, it will be expanded to cover most provinces.