Abstarct: Given the continuous growth and development of power networks, and the increasing use of electrical energy in daily life, it is crucial to ensure a continuous supply of this energy. One essential requirement for achieving this goal is to maintain the reliability of the network at a proper level. The wide-area protection system plays a critical role in quickly detecting and clearing faults. This system should have sufficient reliability as well as high accuracy to prevent fault propagation and mal-operation under non-fault conditions. Therefore, it is necessary to continuously monitor the status of the protection system. To achieve this goal, it is essential to provide a comprehensive model for evaluating the reliability of the wide-area protection system. In this thesis, a comprehensive model is proposed using the Markov modeling method to evaluate the reliability of various equipment in the wide-area protection system, including digital relay, wide-area protection communication system, current transformer, and SF6 high-voltage circuit breaker. Additionally, these Markov models are combined with the Markov models of capacitive voltage transformer, phasor data concentrator, and phasor measurement unit to propose an 18-state Markov model for the wide-area protection system. Through sensitivity analysis using the proposed model, components with a greater impact on the reliability of the system can be identified. The analysis results indicate the proper performance of the proposed Markov model in evaluating the reliability of the wide-area protection system, which can be effective in optimizing maintenance activities to maintain the reliability of this protection system at a proper level.