Six million newcomers, mostly migrant workers from elsewhere in China, have moved to Beijing in the past decade and pushed its population to nearly 20 million people.
The statement posted online Thursday with city government statistics showed 19.612 million permanent residents. The census conducted last year showed Beijing's population up 44.5 percent from the 2000 census.
The change reflects a trend of China becoming more urban. National census results released earlier showed 49.7 percent of China's population now lives in cities, up from about 36 percent 10 years ago.