The article examines the historical processes that took place in the South of Western Siberia in the first millennium AD. It primarily focuses on identifying the earliest sites of newly formed archaeological cultures that help to find out their areas of formation. It suggests a hypothesis about post-Kulaiskaya culture space as a basis for the development of newly formed archaeological cultures. The authors present their point of view on the way of developing basic cultural traits of such archaeological cultures as Odintsovo, Maima, Srostky and Basandajsk, which later became the major cultures determining the course of historical development in the vast region of Western Siberia. On the basis of analyzing different authors’ points of view in their major publications a hypothesis on the major cultural components of the newly formed archaeological cultures and ways of their spreading is put forward. The main center of culture genesis in the South of Western Siberia — the foothills of the Altai territory — is chosen, and the authors give explanation to their choice.