Substation grounding system of Provincial Electricity Authority (PEA) are normally designed using CDEGS software. However, the copyright and limited user licenses affect the practical use. Therefore, using an alternative software should be more beneficial and cost-effective. MATLAB, an engineering software, has been utilized in this study to design the substation grounding system of non-uniform soil. The formulas used in this program are cited from previous literatures and followed the IEEE80-2000. The parameters, including grid resistance (R-g), grid potential rise (GPR), mesh voltage (E-m), and step voltage (E-s), are in accordance with the results from CDEGS software.