Scientific data on the evolution of meliorated peat soils under the impact of agricultural use are presented. The following 3 soil groups are fanned as a result of destruction of a peat layer after drainage of mires: peat soils containing more than 30% of organic matter, organic-mineral and mineral residual-peaty soils containing 15-30% and less than 15% of organic matter, respectively. The classification of each of this group based on the criteria of the morphology of soil profile, ratio between organic and mineral parts of the soil and granulometric composition of mineral bedrock is given. Suggestions about nomenclature of new soils are presented.