The concept of the Final Pleistocene and Early Holocene stone industries in Western Transbaikal is fully determined by microblade component. Thus, the preparation and utilization of wedge-shaped core is one of the most important criteria to define the local culture in the region. The Selenga culture was singled out on materials of the Ust-Kyakhta archaeological area on the basis of complex technical and typological features. With one exception all attributes are associated with wedge-shaped core production and utilization: core metrics; the modes of their transforming from flat cores — the so called “Selenga splitting technique”; the lack of bifaces among the blanks for wedge-shaped cores; as well as associated with them the ski- and rook-like removals. Detailed analysis of wedge-shaped cores from the Ust- Kyakhta-3, a double layer site (Western Transbaikal), previously related to the Selenga culture, allows the authors to significantly extend the list of technological characteristics for the cultural division under study. The next aspects were determined for technology of the wedge-shaped core production: raw material preferences; the shapes of the blanks and core metrics; the modes of keel, wedge and lateral refitting; the striking platform trimming, their oblique angle and the modes of their reduction; as well as the blank chips resulted from their utilization. Besides, the new scheme of the transforming the flat core to wedgeshaped one was proposed as part of the previously defined Selenga technique of the stone treatment.