Experts also warn that the best chance to solve the aging problem will be within the next 25 years. According to a study on China's aging population by the China National Committee on Aging under the State Council, the problem will reach its most critical point between 2030 and 2050.

"The demographic change from an 'adult society' to an aging society took only 18 years in China, compared with decades or even hundreds of years in developed countries," said Li Bengong, Executive Deputy Director of the China National Committee on Aging.

Li said the number of elderly people is expected to reach 248 million by 2020 and climb to a peak of 437 million by 2051. "We have to seize the opportunity to tackle this serious problem or we will regret it later if we miss it," Li said.

"It's the best time to improve China's old age social security system and medical security reforms," said Zhou Xiaochuan, Governor of the People's Bank of China, the central bank.

Employees in China have individual social security accounts, but the money some current workers deposit in their accounts has been used to pay pensions to retirees. As a result, the fund is running a deficit of 800 billion yuan, according to statistics.

"The 800 billion yuan is a big problem but people don't have to worry about that as it is the government's responsibility to make that up and our government is capable of doing that," said Zheng Gongcheng, a social security expert at Renmin University of China.

The ongoing old age security reform has stopped the situation in which employees' deposits are used to pay pensions. But the issues of how to make up the deficit and how to make the different social groups benefit from the reform remain unresolved.

Devising plans

According to the white paper, China is setting up a flexible basic old age pension mechanism that adjusts the basic pension based on salary levels and fluctuations in the prices of goods.

Meanwhile, China is raising old age funds through more diversified channels to be more financially prepared for the expanding aging population. The Central Government is increasing financial subsidies as well.

The government is also encouraging companies to establish annual funds for their employees as a supplementary old age security benefit, which are co-funded by the companies and the employees. Besides, personal savings for old age support are being encouraged, as well as strengthening the old age security system through multiple channels.

With his wife having passed away last year and his two children working abroad, 74-year-old Beijing resident Xing Li is one of the typical "empty nest" members. His daughter tried to persuade him to live with her in Canada or go into a nursing home. But Xing declined, saying, "I might be ill at ease in a foreign country because it's a totally strange place to me. I'd rather stay in Beijing as I feel I belong here."

The "big family" tradition no longer prevails in China and the function of supporting the elderly at home has been weakened, leading to an increasing number of "empty nest" old people.

But, according to Yuan Xin, demographic researcher with Nankai University in Tianjin, supporting the aged at home is the best option, considering China's level of economic development and ethical traditions.

In any case, Xing is lucky. His community began to set up an elder-care center modeled on child-care centers, providing meals, entertainment and rest facilities for the aged where they can stay during the day.

In cities like Beijing such elder-care centers are booming but the number still cannot meet the growing demand. "So far China has close to 40,000 public elder-care establishments and an additional 1,700 started by non-governmental organizations, with a total of 1.5 million beds," said Jia Xiaojiu, an official with China's Civil Affairs Ministry.

To solve the shortage of elder-care establishments, some communities in Beijing began to adopt a practice from neighboring Japan: the "saving time" project, in which younger retirees take care of the older ones or sick ones as volunteers and record their service time. When these volunteers need to be taken care of, they can be repaid with services according to their service time.

In addition, there's a new phenomenon called the old-age apartment, which follows a commercial pattern and is built by real estate developers. The aged live in an apartment alone during the week, and on weekends and holidays there is a family get-together.

"Old people feel lonely when they are separated from their children while their children are too busy to provide a comfortable living space for the elderly, but now the elder-care apartment can to some extent solve the problem," said Shou Lili, who formerly was a researcher at the Shanghai Research Center On Aging.