Langfang (Chinese: 廊坊; pinyin: Lángfáng), is a prefecture-level city of Hebei Province, which was known as Tianjin Prefecture until 1973. Hebei province was renamed Langfang Prefecture after Tianjin became a municipality and finally upgraded into a prefecture-level city in 1988. Langfang is located approximately midway between Beijing and Tianjin. At the 2010 census, the population of Langfang was 4,358,839, of whom 868,066 lived in the built-up (or metro) area made of Guangyang and Anci districts; its total area is around 6,417.28 km2 (2,477.73 sq mi). Langfang borders Baoding to the southwest, Cangzhou to the south (both prefecture-level cities of Hebei), Beijing to the north and Tianjin to the east. Sanhe City and Dachang Hui County are now conurbated with Beijing, so that they form part of the same built-up area. Langfang is the smallest prefecture-level city of Hebei Province by land area.
On June 26, 1900, during the Boxer Movement, belligerent European forces heading towards Beijing were stopped by Boxers at the Battle of Langfang, and were defeated and forced to turn back to Tianjin. The Chinese forces were victorious.
It was the site of another battle during the Second Sino-Japanese War.
Considering Langfang's position between these two prominent cities, Langfang is a relatively green city. Every 300 to 500 m (980 to 1,640 ft) along the city's major streets are parks where local people stroll and take exercise. Langfang's five-kilometer long pedestrian street is now the longest in China. On the other hand, air pollution is a severe problem and in 2013 it was ranked among the 10 worst cities in China for air pollution, along with 6 other cities in Hebei including Xingtai, Shijiazhuang, Baoding, Handan, Hengshui and Tangshan, are among China's 10 most polluted cities.