There are few documents written in Arabic alphabet relating to Kyrghyz History and the Kyrghyz Language. Documents in Arabic which can be found in libraries and archives have been transformed into Cyrillic alphabet owing to the efforts of the scientists. Thus, they do not only throw light on Kyrghyz history, but also require us to be the owners of those documents which are focused on definite stages of the Kyrghyz language. The present work contains the transcribed text of the letter written by Astrahan Kyrghyzs addressed to Ekaterina II in 1775, its Russian translation and the facsimile of the original text. According to the content of the letter Astrahan Kyrghyzs came there from Aksu and Anjian towns. It also says that first they were under the rule of the Hong Taichi Han. Later they were under the control of Hytai, Russia and Kalmuks Donduk Dashy Han, Obucha . After kalmuks had escaped to China, Kyrgyzs together with other Muslims were included to Haji Tarhan Muslims. However, the letter comprises facts about their suffering from Biketaf’s pressure, the governor of Astrahan Province. At the end of their letter Astrahan Kyrgyzs make a request to protect them from his oppression. The language of the letter involves the peculiarities of Eastern Turkic written language of the XVIII century. Moreover, the peculiarities of the Chagatai Turkish, Old Anatolian Turkish and Kypchak Turkish written languages can also be found in the text at the same time. There is no doubt that it is a valuable contribution to the works on Kyrghyz History as well as to the History of the Kyrghyz Language.