In Grey clayey loamy agricultural soils the horizontal and vertical variability of soil density is the dominant factor in the formation of preferential water filtration flow paths. These paths are predominantly formed in zones of soil density categories, taking the vertical orientation of the soil profile. Because the formation of different kinds of soil density category qualities, the subsoil compacted layer (20-30 cm) with median density 1.56 g cm-3 (lower and upper quartiles are 1.21 and 1.72 g cm-3) plays the main role in the organization and space distribution of preferential flow paths.