The history of the Stone Age in Western Siberia is traditionally considered by the researchers as a continuous line of development. Mesolithic Age comes after Upper Paleolithic period, and Neolithic Epoch replaces the Mesolithic. In the South of the territory between the Ob and the Irtysh there are Paleolithic archaeological sites, but any authentic Mesolithic complexes haven#t been found yet. The author believes that at the edge of Pleistocene-Holocene the territory was abandoned by people because of global climatic changes. It was inhabited again in VI millennium B.C. when a migration wave of Kelteminar culture came from the Central Asia because of climate aridisation.