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