Bachu, also known as Maralbexi County, is a county located in the southwest of the Xinjiang Uyghur Autonomous Region in China. It falls under the administration of the Kashgar Prefecture.
The county covers an area of 18,491 km2 (7,139 sq mi) and surrounds the sub-prefecture-level city of Tumxuk, though it does not administer that city. According to the 2002 census, Bachu has a population of 380,000 residents.