In this thesis influence of different soil models on grounding calculation was presented. The first part of this thesis deals with four basic types of grounding systems (working, protective, lightning and combined), grounding types and terms such as: touch voltage, step voltage and potential distribution. Soil resistivity is the basic characteristic of soil which affects a number of parameters (temperature, humidity, salt content). Basic methods of measuring soil resistivity, which were presented in this thesis, are: Wenner method, Schlumberger method, General method, Driven rod (3-probe) method and the Dipole-Dipole method. Soil resistivity measurements are used to obtain an equivalent soil model (uniform model, two-layer horizontal model, multi-layer horizontal model and others). With the simulations in the CDEGS software package (both the RESAP and MALT modules were used) on two different soil models, the resulting affect of soil model on the grounding resistance, potential distribution at the surface, touch and step voltage were shown.