The study of power system of relays requires some previous experience in this field. Laboratories focusing on teaching and researching the area of power-system protection have therefore been amply reported. However, these facilities require the actual presence of the students in the laboratories. To overcome this problem, a power-system-relaying remote laboratory has been developed. To implement this laboratory, a testing system of the relay operating characteristic, together with Matlab-based software, was developed. This remote laboratory enables real power-system-relaying experiments through the Internet. In fact, the user can remotely test a real relay disoperation. This system will therefore allow proficient analysis of sensitivities to relay settings and network configurations.