This paper introduces a multiple attribute decision-making (MADM) method called ELECTRE III and demonstrates its application to power distribution system planning by an example, also proposes a simple ranking way used in the method. The example is a distribution-related problems based on an existing distribution network, ensuring the illustration can be used for reference in similar cases. Meanwhile, that the thresholds may be functions of the performances of the pair alternatives for special criterion is proposed and illustrated in the example. Furthermore, the result of comparison with the simple multi-attribute rating technique (SMART) shows ELECTRE III is more flexible in utilizing the information provided by decision maker (DM) and can overcome the flaw that the capital cost masks the technical benefits. In conclusion, ELECTRE III is a practical and feasible method in power distribution system planning