Liu Lianfeng, 37, an accountant, works in a State-owned enterprise and lives in Beijing with her husband and their 5-year-old son. In 2011, she picked up her parents from her hometown of Dalian, in Liaoning province, to bring them to Beijing.

"My parents raised me in a poor village. I want to make it up to them," says Liu, who bought an apartment costing 1.5 million yuan ($235,900) for her parents.

"But I was busy at work and looking after my son. So, though we lived nearby, I didn't have much time to spend with them and didn't quite realize they couldn't get used to life in Beijing until I found their health condition was declining."

"I think old people like my parents who can't follow changes in society, need love and care from their children more than anything else."

Kou Zhenjie, 54, retired three years ago. She moved to Beijing to look after her newborn grandson for her 29-year-old daughter, who works at a foreign company.

"My biggest happiness derives from my daughter and my grandson, as long as they are healthy and happy," says Kou, who nevertheless admits she feels lonely sometimes and misses her former colleagues and neighbors in her hometown.

"My daughter is so busy and stressed out, what else can I ask from her? She can't follow the guidelines of filial piety, but it doesn't mean she is unfilial," Kou says.

"Filial piety should have two forms. One is the cultural and moral sense that children should show their filial respect; the other is economic responsibility, which is not only the responsibility of children but the whole welfare system," says Tang Jun, a social policy researcher with the Chinese Academy of Social Sciences.

By 2011, China had 167 million people over 60, or 12.5 percent of its population. The UN's definition of an aging society is 10 percent.

By 2020, the elderly population will reach 243 million and this aging will speed up until 2030, when the country will become the world's most aged.

Meanwhile, due to the predominance of single child families, children born in the 1980s will need to feed and look after their parents.

"China is facing a problem of nursing and feeding its aging population," says Mu Guangzong, a professor at the Institute of Population Research, Peking University.

Chen Wenhui, assistant chairman of the China Insurance Regulatory Commission, the country's insurance regulator, admits there is a huge shortage of retirement funds at a meeting in July.

"It has become a burden for families and society. Unless our government and the whole of society works together to cope with the challenge, China's elderly will hardly have a secure future."

Contact the writer at wangru@chinadaily.com.cn.