Lanxi City, a county-level city under the jurisdiction of Zhejiang Province, is administered by Jinhua City. It is located in the central and western part of Zhejiang Province, the middle reaches of Qiantang River and the northern margin of Jinqu Basin. Its geographical coordinates are 29°1'20" -- 29°27'30" north latitude, 119°13'30" -- 119°53'50" east longitude. It is 67.5 kilometers long from east to west, 38.5 kilometers wide from north to south, 20.5 kilometers from Jinhua city and 132 kilometers from Hangzhou. The total area is 1313 square kilometers. According to the seventh census data, as of midnight on November 1, 2020, the permanent population of Lanxi was 574,801.

Annals of Lanxi County of Guangxu opened with Emperor Ming and clear Shui, "Though small and narrow, the city should be four streams. Set the party, that is the important area of east Zhejiang, Xun not slander also." Wu and Qu rivers converge to form LAN River at the foot of Lanyin Mountain, and then converge to Meicheng and Xin 'an River in the north, which is called Fuchun River. Continue to the north, below Fuyang, which is called Qiantang River. Since ancient times, Lanxi has been known as "the confluence of three rivers", "the waist of six rivers" and "the thoroughfares of seven provinces".

The city borders Jindong District and Wucheng District of Jinhua City in the southeast, Longyou County in the southwest, Jiande City in the northwest, and Pujiang County and Yiwu City in the northeast. The city water system of Lanxi belongs to the Qiantang River system, which is mainly composed of three rivers (Qujiang, Jinhua and Lanjiang) and five rivers (Meixi, Ganxi, Chixi, Youbu and Mada). Camphor and orchid are the city trees and flowers respectively. Lanxi is a 4A scenic spot city and one of the second batch of pilot areas of Zhejiang high-quality development and construction common prosperity Demonstration Zone.

In 2022, the GDP of Lanxi was 46.508 billion yuan.