Across its Central Asian distribution, the saxaul sparrow occurs in six probably disjunct areas, and is divided into at least three subspecies. The nominate subspecies Passer ammodendri ammodendri inhabits three of these areas, one in the Syr Darya basin of Kazakhstan and Uzbekistan, and another to the south of Lake Balkhash and the north of Almaty, where it is only common in the valley of the Ili River. In a third area, sometimes recognised as a subspecies korejewi, ammodendri birds breed sporadically in parts of central Turkmenistan, Iran, and possibly Afghanistan, migrating to the south during the winter. The subspecies stoliczkae was named after Ferdinand Stoliczka in 1874 by Allan Octavian Hume, from specimens Stoliczka collected in Yarkand. This subspecies is separated from the other two subspecies by the Tian Shan mountains. It is found across a broad swath of China from Kashgar east to the far west of Inner Mongolia, through the areas around the Taklamakan Desert (but probably not in the inhospitable desert itself), and through the east of Xinjiang, northern Gansu, and the fringes of southern Mongolia. In the extreme west of the Gobi Desert a disjunct population separated from the other stoliczkae birds by the Gurvan Saikhan Uul mountains occurs, which is sometimes separated as a subspecies timidus. The subspecies nigricans, described by ornithologist L. S. Stepanyan in 1961, is found in northern Xinjiang's Manasi River valley.