It is very important to creatively have the rich written heritage of the past centuries in order to study the culture and history of the Central Asian states in the Middle Ages. Persian language data has a special place among written monuments. The narrative historical works of the authors of the Middle Ages, which reveal the history of Central Asia in the XIV-XV centuries, mainly consist of the works of the Timur generation group. Timur works are among the data that have not lost their importance in terms of scientific consistency to this day. They describe not only the policy of Timur and his descendants towards neighboring countries and peoples, but also a lot of material about their internal political, economic, ethnic and cultural life. In the article, the author collects information from the history of many clans and tribes that lived in the Middle Ages and later became part of the Kazakh people, based on Timur’s data. The author collects data related to the history of Timur and examines opinions related to the study of Timur’s works. It tells about the tribes that lived in the Middle Ages, including the history of the Zhalayir tribes based on their Timur works. The author identifies and describes the famous people mentioned in Timur works in the Middle Ages with the names of clans and tribes.