The results of complex study of Late Pleistocene loess deposits of key section Lozhok of loess-soil sequence of Novosibirsk Ob’ region are presented in the paper. Grain-size distribution data is considered. It evidenced about the intensification of environmental dynamics to the Last Glaciation. It is showed that the conclusion about greater accumulation loess activity during the Bagan time is  confirmed also by loess accumulation rate calculations.