Tien Shan, or Tian Shan, a mountain range in Kyrgyzstan and the Xinjiang region of China. The name is Chinese for “Celestial Mountains.” The range extends east-northeast from the Pamirs for some 1,500 miles (2,400 km), forming part of the border between Kyrgyzstan and China. On the border is the highest peak—Pobeda (Victory) Peak, 24,406 feet (7,439 m) high. The Turfan Depression, near the range's eastern tip, drops to 505 feet (154 m) below sea level. The Syr Darya, Chu, Ili, and many other rivers originate in the Tien Shan. Rain and snow are heavy and frequent on the northern slopes. There are many glaciers.

Only the central and western sections of the Tien Shan have been extensively explored. Soviet scientists began to conduct geological and mineral surveys in the Kyrgyz section in the 1940's.