Late Pleistocene and Holocene polygonal-wedge ice is studied in the lower course of the Yenisei River. Ice distribution, features of the formation, chemical and microbiological composition were determined. It was established that ice wedges were formed on the slopes of the depression, in coastal-marine lagoons and in thermokarst during Holocene. The evidence of thermoabrasion and thermokarst in sediments as well as the marine signal in composition of polygonal-wedge ice allowed clarifying the southern limit of the Holocene transgression.