northwestern china is made up of shaanxi, gansu, and qinghai provinces and ningxia and xinjiang autonomous regions. it is china's poorest and driest region. it is also where most of china's muslims live. the largest city in the region is xi'an, the capital of of shaanxi province. northwest china is where the silk road used to be. food in northwest china is often made of mutton, beef, spices, and wheat.