The fall-of-potential method is commonly used in measuring the ground resistance of large-scaled grounding system and the current and potential auxiliary electrodes are horizontally arranged. Because the distances between the ground grid to be tested and auxiliary electrodes are limited in downtown areas, it is very difficult to measure accurately the ground resistance of large-scaled grounding system. In this paper, the fall-of-potential method of measuring the ground resistance with the vertically-placed current and potential auxiliary electrodes was examined and discussed. The validity and good accuracy of the proposed method of measuring the ground resistance were confirmed through various simulations and actual tests carried out in uniform and two-layer soil structures.