Abstract-In this paper, a frequency-domain-based transient electromagnetic model of grounding system in horizontally stratified multilayer medium is presented. The basis of the model is an improved version of the time-harmonic electromagnetic model of grounding system. Using the originally developed continuous numerical Fourier transform algorithm, the results obtained by the time-harmonic model are synthesized into a complete time domain solution. The presented model features very high accuracy and fast execution speed and is validated through several numerical examples.