By Xu Xingtang, Wang Yaguang and Zhu Shaobin

The G20 Summit on Thursday in London is entrusted with hopeful task of rescuing the world economy from a downturn. Many pin their hopes on China to bolster the teetering global economy.

In a flood of media reports, China has been described as a "knight" who will save the world from the recession -- after all, it is the world's third largest economy, holding 2 trillion-US-dollar foreign exchange reserve in hand and the only major economy reporting growth when others were faltering.

But is China able to rescue the world?

Although China's economy has boomed in recent years, it still accounts for just 6 percent of the global economic output and contributes less than a fifth of the United States' figure.

Equivalent to the size of China's economy is a massive population of more than 1.32 billion, or nearly 20 percent of the world total. The per capita gross domestic product (GDP) of China ranked after 100 on the world list.

The country's GDP topped 4.32 trillion US dollars in 2008, based on the whole year's average exchange rate of 1 US dollar against 6.948 yuan. However, its per capita GDP was only 3,266 US dollars.

According to the National Bureau of Statistics, China's rural per capita net income reached 4,761 yuan (697 US dollars) last year and urban per capita disposable income came to 15,781 yuan. A total of its 40.07 million rural population still live below the country's 1,196-yuan poverty line.

As the global financial crisis deepens, China is not immune. Its GDP growth slowed to 9 percent last year compared with an annual 13-percent increase in 2007.

Exports, one of the bedrocks to fuel China's high growth in recent years, plunged 17.5 percent year-on-year in January and a bigger 25.7 percent in February because of weakening external demand.

The falling exports have led to slowdown in industrial production, factory shutdowns and rising unemployment.

All the difficulties and uncertainties have prompted the Chinese government to stimulate the economy with a series of aggressive measures since late last year. These included a 4-trillion-yuan stimulus package, a plan to expand rural home appliance purchases and support plans for key industries.