Jiuquan, formerly known as Suzhou, is a prefecture-level city in the northwesternmost part of Gansu Province in the People's Republic of China. It is more than 600 km wide from east to west, occupying 191,342 km², although its built-up area is mostly located in its Suzhou District. As of the 2020 census, its population was 1,055,706 inhabitants but 768,274 lived in the built-up area made of Suzhou urban district and Jiayuguan City now being conurbated.