Kucha, or Kuche (also: Kuçar, Kuchar; كۇچار, Кучар; , ; कूचीन), was an ancient Buddhist kingdom located on the branch of the Silk Road that ran along the northern edge of what is now the Taklamakan Desert in the Tarim Basin and south of the Muzat River.
The former area of Kucha now lies in present-day Aksu Prefecture, Xinjiang, China. Kuqa town is the county seat of Aksu Prefecture's Kuqa County. Its population was given as 74,632 in 1990.
The history of toponyms for modern Kucha remain somewhat problematic; however, it is clear that Kucha, Kuchar (in Turkic languages) and Kuché (modern Chinese), correspond to the Kushan of Indic scripts from late antiquity.
While Chinese transcriptions of the Han or the Tang imply that Küchï was the original form of the name, Guzan (or Küsan), is attested in the Old Tibetan Annals (s.v.), dating from 687 CE. Uighur and Chinese transcriptions from the period of the Mongol Empire support the forms Küsän / Güsän and Kuxian / Quxian respectively, instead of Küshän or Kushan. Another, cognate Chinese transliteration is Ku-sien.
Transcriptions of the name Kushan in Indic scripts from late antiquity include the spelling Guṣân, and are apparently reflected in at least one Khotanese-Tibetan transcription.
The forms Kūsān and Kūs are attested in the 16th century work Tarikh-i-Rashidi. Both names, as well as Kos, Kucha, Kujar etc., were used for modern Kucha.
Chinese names of Kucha – 曲先; 屈支 屈茨; 丘慈 丘玆 邱慈; 俱支曩; 歸兹; 拘夷; 苦叉 and; 姑藏 – have been romanized as Quxian, Quici, Chiu-tzu, Kiu-che, Kuei-tzu, Guizi, Juyi, Kucha, and Guzang. Although 龜玆 has sometimes been romanized as Qiuzi (or Wade-Giles: Ch'iu-tzu), this is generally regarded as incorrect; the second syllable is more properly represented as ci (Wade-Giles: tz'u).
For a long time, Kucha was the most populous oasis in the Tarim Basin. As a Central Asian metropolis, it was part of the Silk Road economy, and was in contact with the rest of Central Asia, including Sogdiana and Bactria, and thus also with the cultures of South Asia, Iran, and the coastal areas of China.