As China's urban population reached 46 percent of the total population last year, Chinese urban dwellers became the largest such population in the world, according to a 'blue paper' released on Thursday.

By the end of 2009, China's urban population reached 620 million as both the annual birth rate and the total urban population became the world' s largest, according to "City' s Blue Book: China's Urban Development Report No. 3," which has been released by the Chinese Academy of Social Sciences and the Social Sciences Academic Press.

It said China's urban population is twice that of the population of the United States and one quarter more than the total population of 27 countries of the European Union.

By 2015, urban residents in China will make up about 52 percent, and by 2030, 65 percent of the total population in the country, it said.

"A milestone change for urban development will take place when urban people make up more than 50 percent of the population and thus surpass the number of rural people," the paper said.

"The 50-percent point phenomenon will occur in the mid-12th Development Program period (2011-2015) when both the number of urban and rural Chinese will reach 680 million," it said.

The role of the urban economy will be further strengthened by that time, it said, adding that the urban economy would continue to drive the domestic demand.