Niu Wenyuan, a senior scientist with the Chinese Academy of Sciences (CAS) said that China must speed up the development of its three metropolitan areas on its coast line and make them new powerhouses to boost the country's urban construction.

Niu made the remarks at the China Mayor Forum which opened Monday in Guangzhou, capital city of South China's Guangdong province.

Niu is also the chief scientists among authors of the China Urban Development Report, an annual authoritative report on China's urban development.

The report regards it a top strategy to first develop the three metropolitan areas: the group of cities around the Bohai Bay, the Yangtze River Delta and the Pearl River Delta.

Niu said this may help form a coordinated development among China's big, middle and small-sized cities, shorten gaps between the urban and rural areas, and avoid a blind expansion of a single city.

Niu said currently, the three metropolitan areas only contributed 37 percent of China's total Gross Domestic Product (GDP), which is 30 percentage points lower than the contribution of the US-based three metropolitan areas to the total GDP of the United States.

The figure is also 32 percentage points lower than the contribution of the Japan-based three metropolitan areas to the Japan's total GDP, said Niu.

According to the China Urban Development Report, only when the contribution of the three metropolitan areas to China's GDP rise to 65 percent, they may really become the country's economic centers and help release development pressures on the other areas of China.