Osrušana (Persian: اسروشنه) or Ustrushana [a] was a former Iranian region[1] in Transoxiana, home to the Principality of Ushrusana, an important pre-Islamic polity of Central Asia.

Knowledge of the ruling family of Ushrusana is derived from the accounts by Muslim historians such as al-Tabari, al-Baladhuri, and Ya'qubi of the final subjugation of that region by the Abbasid Caliphate and the submission of its rulers to Islam.

On this last occasion, the Muslim army was guided by Haydar (Khedar), the son of the Afshīn Kāwūs, who on account of dynastic troubles had sought refuge in Baghdād.

His dynasty continued to reign until 280/893 (coin of the last ruler Sayr b. Abdallāh of 279 [892] in the Hermitage in St. Petersburg); after this date, the country became a province of the Sāmānids and ceased to have an independent existence, while the Iranian element was eventually almost entirely replaced by the Turkic.However, during the reign of the caliph al-Mahdi (775-85) the Afshin of Oshrusana is mentioned among several Iranian and Turkic rulers of Transoxania and the Central Asian steppes who submitted nominally to him.

[5] But it was not until Harun al-Rashid's reign in 794-95 that al-Fadl ibn Yahya of the Barmakids led an expedition into Transoxania and received the submission of the ruling afshin, Karākana,[6] who had never previously humbled himself before any other potentate.