As the number and complexity of AC substation increase, the need for accurate design procedures for the grounding systems becomes more important both from safety point of view and from financial considerations. The boring test samples and other geological investigations often provide useful information on the presence of various layers and the nature of soil material, as its resistivity and the range of values at the site. THIS BOOK discuss New theoretical developed methods for calculation the earthing resistance and earth surface potentials of variant electric substation earthing systems, i.e., starting from a grid consists of one mesh or rod to a final design consisting of many regular meshes or rods respectively. An experimental work is carried out on an improved scale model to study the behavior of earthing systems in non-uniform soil structure.