Abstract <p>The review summarizes the information about the properties of postagrogenic soils with a focus on the composition of soil organic matter (SOM) during the natural self-revegetation. Within one landscape zone, the contrast in the changes in acidity, SOM content, its stock, and enrichment of humic substances in N decreases from the chronosequences of the arable horizon with the poorest substrate to the richest. This trend is also typical of the series of postagrogenic soils, namely, (sub)taiga sandy and sandy loam soils–(sub)taiga clay loam soils– (forest-)steppe clay loam soils. The pH value and mobile K content decrease in the old arable horizon of the (sub)taiga in the course of natural self-revegetation but remains unchanged in the (forest-)steppe. The content of mobile P and exchangeable Ca and Mg somewhat decreases in the sandy soils of (sub)taiga and is constant in the loamy soils of (sub)taiga and (forest-)steppe. The content of SOM and total N follows different patterns during postagrogenic succession in the sandy soils of boreal and temperate forest biomes. As for the clay loam soils of (forest-)steppe biomes, their content increases or remains at almost the same level during self-revegetation. The nonsilicate compounds of transition metals and mobile calcium compounds, as well as reactive oxygen species produced by soil microorganisms play an important but still vague role in SOM stabilization and decomposition. In the context of postagrogenic regradation changes in soils, only pilot assessments of the transformation of SOM composition are performed.</p>