In this Study, fuzzy logic is used to identify faults that may occur in a radial power system. In addition to the design concept of fuzzy logic based on protective relay, its architecture and application of the developed prototype system are discussed. A digital relay is designed and tested in a laboratory environment using a developed prototype. In order to constitute a new approach to digital protection purpose, fuzzy logic is used instead of conventional protection approaches. The relay proposed here is developed using conventional relay characteristics by adding some abilities, i.e., to distinguish whether the fault is sub-transient, transient, or permanent, to determine whether the fault is one of the types known as phase-to-phase, phase-to-neutral, double phase-to-neutral, or balanced three phase. Performance analysis is performed and the results obtained are given using graphical illustration to show validity of the proposed relay.