Mengzi (Chinese: 蒙自; pinyin: Méngzì; Hani: Maoqziif Siif) is a city in the southeast of Yunnan Province, China.

[3] It is situated in the centre of a fertile valley basin on the Yunnan-Guizhou Plateau[2] 1,310 metres (4,300 ft) above the sea level and was home to about 590,300 inhabitants as of 2021 census.

In 1886, following the war between France and the Qing China, a series of treaties designated Mengzi as a trade port in Yunnan province for the import and export of goods via Tonkin, currently the Northern Vietnam.

[14] Communications were inconvenient: goods from Hanoi or Haiphong were shipped to Hekou on the Vietnamese border by junk, transferred by small craft to Manhao, and then taken 60 km (37 mi) by pack animal to Mengzi.

Throughout the late 19th and early 20th century, Mengzi was a major trading center for commerce between the interior of Yunnan and the Tonkin.

Apart from a brief respite during the early days of World War II, the town of Mengzi has, nevertheless, steadily declined in importance ever since.

When the Japanese invaded Beijing and Tianjin in the late 1930s, university professors, students, and administrators there were forced to leave and travel south to Changsha.

The School of Arts and Law was located in Mengzi, but moved to the provincial capital of Kunming about half a year later.

Recent policy developments have promoted economic growth, leading to substantial changes in the local industry structure and employment landscape.

It is home to numerous historic sites, though many of its splendid structures were damaged or destroyed primarily during the Taiping Rebellion[2][23] and the Cultural Revolution in 1960s.