Langfang does not belong to Beijing, but a prefecture-level city in Hebei Province. Langfang, located in the east-central part of North China Plain, is the nearest city in central China with a total area of 6,429 square kilometers. Langfang City is located in the middle and lower reaches of Haihe River Basin and is known as the "lower tip of Jiujiang". The name of Langfang originated from Yangguang County in the pre-Qin period, Yangguang County was located in Ji Cheng and Yan Dou was located in Qin, so Yangguang City was the old name of Beijing. Today, it is named as the district, which can be regarded as Langfang city with the same origin as the capital.

Influenced by geological structure, most of Langfang city is located in the depression area. With the subsidence of the earth's crust, the ground is gradually filled with Quaternary sediments, which leads to a large subsidence thickness of Cenozoic strata. The terrain of the whole city is relatively flat and monotonous, generally 2.5 ~ 30m above sea level, with an average elevation of about13m.

Langfang City is located in the mid-latitude zone, with a continental monsoon climate of warm temperate zone and four distinct seasons. Summer is hot and rainy, winter is cold and dry, spring is dry and windy, and autumn is refreshing and cool.

The main water systems in Langfang are Chaobaiji Canal, North Canal, Yongding River, Daqing River and Ziya River. Besides the South Canal, the main flood channels in Haihe River Basin flow through Langfang City.