Gansu province in the upper Yellow River valley in northwest China was named after the first character of the names of its two ancient cities, Ganzhou (modern Zhangyi) and Suzhou (modern Jiuquan).

Long and narrow in shape, it has an area of more than 450,000 square kilometers. It neighbors Shaanxi, Sichuan, Qinghai, Xinjiang, Ningxia and Inner Mongoliah, with a diversified topography.

Most of its middle and east parts are of special loess topography, the Hexi Corridor in northwestern Gansu is of green land and the Gobi Desert intermittently spread. The Hexi Corridor occupies the fortress of the ancient Silk Road.