The article provides an overview of written sources in the course of the study by Arab researchers of the Kazakh land of the IX-X centuries, the analysis of the names of the waters of the Earth is carried out. At the same time, their writings dealt with the similarities and differences in the names of the earth's water and compared it with its current names. The first studies were conducted on the Kazakh land in the Middle Ages. The beginning of the research was laid by Arab travelers. Arab and Persian researchers mapped Kazakh lands. Special attention was paid to local names. Especially the names of rivers and lakes are still preserved. The entries are written in an old inscription. The article uses data from the Central Archive of the Ottoman Empire. The research papers present an analysis of valuable data from electronic libraries. An overview of ancient cities, their life, traditions of the peoples who inhabited them is given. The works of each researcher were analyzed, compared with the names on the map of modern Kazakhstan and conclusions were drawn. The climatic conditions of ancient cities and the hydrological regime of rivers and lakes are geographically analyzed. The ancient map-scheme of the researchers was compared with a modern geographical map and a comparative geographical characteristic was compiled. In the Middle Ages, Arab travelers left valuable geographical data about the Kazakh land.