ČÍK Anton: Soil hydraulic conductivity changes depending of tree species, soil depth and stand age in the mountain region of Poľana. Thesis supervisor: Ing. Marián Homolák, PhD. Zvolen 2021. Diploma work, TU in Zvolen, LF, KPP. 51 pp. The presented thesis deals with soil hydraulic conductivity research depending of tree species effect, soil depth and stand age in the mountain region of Poľana. Samples required to measuring of soil hydraulic conductivity and subsequent analysis came from spruce and beech stand and we also had soil samples available from NRP. In order to determine the effect of soil depth on the hydraulic conductivity of soil, samples were taken from two different depths (0-10 cm, 20-30 cm) and subsequently, in addition to these two depths, also evaluated for a total depth of 0-30 cm. To assess the effect of age on soil hydraulic conductivity, samples were taken from seven age levels for beech stands and six age levels for spruce stands, with one age level representsa period of 20 years. Analysis of research results point out that soil hydraulic conductivity within observed areas indicate rather wide span of values. By comparison of soil hydraulic conductivity on the basis of tree species composition we can state that higher values of soil hydraulic conductivity were measured in beech stand (261,56 cm.day-1) in comparison to spruce stand (112,77 cm.day-1). From the point of soil depth, we noticed the biggest hydraulic conductivity in the minimum monitored depth of 0-10 cm. This difference as compared to depth of 20-30 cm was more than twofold. From the analysis of the results, it can be stated that the tree species, the soildepth and the stand agestatistically significantly affect the measured values of the soil hydraulic conductivity. The fact is that soil hydraulic conductivity is conditioned mainly by soil diversity and its physical and chemical properties.