Conducting soil studies are relevant in determining the subordination of forest types and biodiversity of vegetation to soil taxa, in determining the dependence of basic forest stand productivity from soil conditions, in creating a land registry and economic assessment of forest land, in studying the soil evolution of forest plantations under the impact of anthropogenic influences. Soil is the most important environmental factor in shaping the productivity and biodiversity of forest phytocenosis. The study of forest soils is also important in terms of basic research of their genesis, evolution. The article presents the results of research of soil conditions of vegetation growth of forest ecosystems of northern regions of Volga of the Republic of Tatarstan. The main types of forest soils are characterized in the paper. The studied forest formations grow on various soils on genesis and forest vegetation properties: sod-podzol, gray forest, brown forest, brown forest sandy, alluvial meadow, rendziny soil. The granulometric structure of soils varies from sandy to the clay. The well structured soils are formed on loamy layers under forest phytocenosis canopy. Pine and spruce ecosystems have a medi-decomposed litter of moder and multi-moder types; linden, oak, birch and aspen biogeocoenoses have strong-decomposed litter of multi type, that characterizes the intense biological cycle of substances in forest ecosystems. The wide range of place conditions of territories causes the biological diversity of forest vegetation at the level of species and ecosystems.