The paper presents the results of the analysis of the main HV/MV(LV) substation earthing system parameters. Typical parallel driven four- and three-rod earth electrodes are analysed, including the effects of the horizontal, connecting conductors. The influence of metallic objects buried in close proximity to the earth electrodes on the main system characteristics and on the transferred potential is also studied. The results are presented in a generalised form, and can be used in practical design.