Ali Prefecture is located in the west of Tibet and the southwest of the Qinghai-Tibet Plateau. It is about 700 kilometers long from east to west and about 680 kilometers wide from north to south. It is connected to Nagqu Prefecture in the east, Shigatse City in the southeast, Kashgar and Hotan Prefectures in Xinjiang in the north, and Kashmir, India, Nepal and other countries in the southwest. It covers an area of ​​345,000 square kilometers and has an average altitude of more than 4,500 meters. It is known as the "roof of the roof of the world" and the "plateau on the plateau".