China's mega city: the country's existing mega cities
There are over 160 cities in China will more than a million residents. In addition, there are several cities with metropolitan areas with more than 10 million residents – qualifying them as "mega-cities".
Straddling the Yangtze river in the south west, Chongqing became the world's largest municipality on 14 March 1997, when Chinese planners merged together 19 districts, 17 counties and four autonomous counties to create a population of 31.4 million.
Arguably China's largest true city, since Chongqing incorporates a huge swathe of countryside into its municipality, Shanghai's larger urban area is home to at least 20 million people, around half of whom are migrants from other areas in China.
The capital of China has a greater urban population of 18 million people, and is rapidly spreading towards the coast as more and more Chinese are drawn to the centre of the country's political and economic decision-making.
A short distance from Hong Kong, China's southern capital has an official population of 10,334,000, according to the local government at the end of 2009. However, the sprawl of factories extending from the city in all directions means its true population could be far higher.
The last of China's five key "National Central" cities, Tianjin lies on the north east coast and has become a major hi-tech centre and the site of China's first Airbus factory. Its municipal population is thought to be higher than 12 million.