the most N.W. province of China, lying between N. Lat. 32, 30, and 40°, and E. Long. 98, and 108°, and bounded on the N. and W. by Mongolia, into which it projects a long tongue of land, E. by Shen-si, and S. by Shen-si and Szuchuan. The surface is mountainous, some of the peaks rising to more than 10,000 feet above the level of the sea. The principal river is the Hoang-ho, or Yellow River, which flows in an easterly direction through the province. The climate is rather cold; and the soil in general sterile. Wild animals abound, and large flocks of cattle are kept in the province. The capital is Lan-chou. Pop. about 16,000,000.