At frequencies, quasi static method can be used to analyze grounding networks. In this case, all wires of a grounding network are regarded as having an equipotential due to low frequency or some low frequency approximated processing is used. However, for lightning subsequent return strokes, the frequency components could be up to 20 MHz. In this paper, a very accurate full-wave frequency domain algorithm related to multi Sommerfeld integrals is used to accurately analyze the grounding network in order to design a suitable grounding protection system. A compact representation is given of the electric-and magnetic-type dyadic Green's functions for plane-stratified, multilayered soils based on the transmission-line network analog along the axis normal to the stratification. Using a combination of the discrete complex image method, the Sommerfeld integrals can be finished very quickly.