It is generally accepted that climate and vegetation cover change within the platforms during the Cenozoic time were more significant than the relief transformations. In this regard, climatic and geobotanical factors are leading in revealing the features of geosystem transformation. But this approach is debatable when we need to research the transformation of platform geosystems located near the centers of tectonic activity. The geosystem transformation research is especially relevant for the Lena-Angara plateau. Its formation is considered to be the result of the influence of the Baikal rift zone on the Siberian platform margin. The problem of physico-geographical zoning and the correlation of physico-geographical districts and provinces to the higher divisions remain relevant for this territory as ever. The territory is characterized by the diversity and contrast of geosystems, which makes the area of research a unique testing ground for revealing the factors of their transformation. In addition, the identification of leading factors and direction of the spaciotemporal transformations of the geosystems of the Lena-Angara plateau remains the issue of concern. The influence of neotectonic processes on geosystems transformation in the area of research has not been practically considered. The previously published materials to address the problem require their systematization from the perspective of an integrated approach. The paper presents the generalized information results obtained in the process of field research, after the analysis of literary and cartographic data with a view to identify the specifics of the plateau geosystems transformation. It is determined that within the plateau there were four periods of irreversible geosystems transformation, which were caused by the synchronous manifestation of climatic and neotectonic processes.