It the second half of the 5th с. ВС, during the transition from Sauromatian to Early Sarmatian (Prokhorovka) archaeological culture, some important changes in burial rite and inventory took place in the Southern Urals. They were connected not only with furher development of the society and its inner transformation, but also with an influx of newcomers. Shaft-chamber tombs with south-oriented corpses may be connected with this new population. The territory where the tradition of interment in shaft-chamber tombs and catacombs was observed in the half if the 1st mill. ВС was Norton and North-Eastern China, the tradition of shaft-and-chamber tombs being one of indications of the cultural entity that existed in this region. One may suppose that it was from North-Eastern China (Eastern Turkestan) that the core of the newcomers migrated to the steppes of Kazakhstan Urals, and first of all to the Soutern Urals. The first mass migration, as it seems, consisted of several consequent waves that took place during a short period of time, most probably in the third quarter of the 5th с. ВС. In the 4th century migrations were nto so large-scale. At that time, only small tribal units moved to the West, mainly to the Southern Urals and mixed with kindred tribes. It is difficult to account for the reasons that caused the nomads of Eastern Turkestan to move to the West. These reasons cold be connected either with climatic shift in the region or with political developments on the northern and north-western borders of China.