Presented are the results from investigating glacial terminal basins of Eastern Transbaikalia. The formation conditions are examined for lake basins. This paper provides examples of the parameters of the glacier snout-caused overdeepening crystalline rocks and unconsolidated deposits of intermontane basins. The Late Pleistocene age of the lake basins is determined by the paleogeographical restoration of the ancient glaciations of Transbaikalia. The terminal lakes are direct indicators of the maximum distance of mountain-valley glaciers from the centers of the last glaciation. They Bol’shoe and Maloe Leprindo, Zarod, Nichatka, Oron, Chitkanda and other lakes. Paleoglaciological restoration of glaciation, and analysis of the neotectonic block structure of the relief determine the genesis of lake depressions occurring in glacial areas. Morphogenetic analysis of terminal formations substantiates the priority of exogenous processes over endogenous processes in the formation of lake basins. The influence of endogenous forces is limited by selective exaration of rocks that are weakened by intense tectonic fissuring. The lake preservation conditions and the dynamics of the filling of glacial lakes with terrigenous material in the Late Pleistocene-Holocene are assessed.Keywords: Pleistocene glaciation, glacial amphitheater, terminal moraine, glacial-lobe lake.