Riwoche — an extremely primitive, small-sized breed (or isolated population) of domestic horses inhabiting the high-mountain plateau of Riwoche in the eastern part of the Tibet Autonomous Region of China at altitudes of 4000–5000 m. One of the smallest horses in the world, retaining an archaic appearance close to Przewalski's horses. Height at withers 1050–1200 mm, live weight 160–230 kg, body length 1300–1480 mm, chest girth 1350–1480 mm. Build is strong, compact, "pony-like", with short limbs and a relatively large head. The head is relatively large (length 380–440 mm), forehead wide and convex, profile straight or slightly concave. Ears small, erect (length 110–135 mm). Eyes relatively large, widely set, dark brown. Neck short, thick (length 420–520 mm). Body compact, barrel-shaped, with a short back (back length 420–480 mm). Limbs very short and strong, hooves small, strong, cup-shaped (diameter 95–110 mm). Tail set low, dense, relatively short. Coat very dense, coarse, with abundant undercoat in winter; in summer — short, tightly fitting. Dominant color — bay of all shades, often dun and mouse-gray with pronounced primitive markings: dorsal stripe, zebra stripes on legs, "wings" on shoulders, mask on muzzle and light spectacles around the eyes. Differs from the base type by extremely small stature with strong constitution, high expression of primitive markings, short-leggedness and "pony-like" body format. Format index ≈ 1.15–1.22, massiveness index 1.45–1.55, head 38–40 % of height at withers.