The article analyzes the activities of the archaeologist E.A. Smagulov (1952-2019). Under the influence of his mentors (L.B. Erzakovich, V.M. Masson, K.M. Baipakov), he made the city and the fortress of the oases of South Kazakhstan in ancient and early medieval times the main object of research. In 1996 he created the Turkestan expedition and concentrated on the study of the Turkestan oasis. For the first time he managed to explore and excavate large areas of important monuments with raw construction – the cities of Sauran and old Sauran (Karatobe), Shavgar (Shoytobe), old Yasy / Turkestan with the early citadel of Kultobe, the most important pre-Islamic religious center Sidak, the Golden Horde city of Zhayik. A significant topic of his work was the study of the early strata associated with the first state in the region – the “nomadic empire” of Kangjui and the descendants of its population. He considered the history and culture of Kangjui in connection with both more southern oases and nomadic Sarmatians. E.A. Smagulov fought for the creation of continuous protected areas around Sauran and old Turkestan to preserve historical landscapes; He paid much attention to the restoration and museumification of the studied monuments, the promotion of scientific knowledge. Most of all, he was interested in the history of the planning of settlements and dwellings, the development of burial structures and related rituals, crafts related to ceramics and non-ferrous metals, tamga signs. A special place in his research was occupied by the local pre-Islamic Mazdeanism, its temple complexes in Sidak and Kultobe and their comparison with the materials of the southern and eastern neighbors. An erudite specialist, he possessed an analytical mind and, on the basis of local materials, solved general issues of the history and culture of Central Asia.