Beijing's population is nearing the 17 million mark, and according to demographic experts, one in four residents is a migrant from another country.
According a report by the official Xinhua news agency, the population of Beijing is currently pegged at 16.95 million as of December 2008, which is up by 620,000 from a year earlier.
The agency quotes the Beijing Municipal Bureau of Statistics spokeswoman Yu Xiuqin as saying in a statement: The population in Beijing has been swelling rapidly over the past four years.
Beijing's population was 15.38 million in 2005, 15.81 million in 2006 and 16.33 million in 2007. The 2005 figure was up 453,000 from 2004.
Yu said there were several challenges that required attention, such as resources and the environment, which were affected by rapid population and economic growth and social development.