Continuously increasing consumption of electric energy especially in developing countries and for many strategic consumers in which electricity failure would cause irreparable damages, have made the reliability issues as an important factor in electrical energy generation, transmission, and distribution systems. In order to supply ever increasing demand in acceptable level of system reliability, the number and capacity of power plants, transmission lines and distribution network should be expanded, and power transfer to neighboring networks is inevitable. The main challenge toward power system development is the remarkable increment in the network short circuit current level as a result of the network equivalent Thevenin impedance reduction. Consequently, network equipments will face higher fault currents, mechanical forces, and temperature rise during the failures. Among the various methods for Limiting short circuit current level, utilization of Fault Current Limiter (FCL) technology is more easy and economic. Installation of FCL is possible without t long time load curtailment being imposed on the power systems. However, installation of FCL in a substation imposes new fault modes and as a result substation reliability indices will be varied. In order to quantitatively clarify these variations reliability indices, this thesis investigates all fault modes related to the various configurations of high voltage substations including: single busbar single breaker, double busbar single breaker, ring busbar, one and half breaker design, and double busbar double breaker with the presence of FCL and without it and failure and annual outage rate indices are calculated. These indices have been utilized for investigating the effects of FCL on the substation reliability. Furthermore, the effect of FCL on various sections of distribution system has been investigated. For this purpose, System Average Interruption Frequency (SAIFI), System Average Interruption Duration (SAIDI), Average Service Availability (ASAI), and Energy Not Supplied (ENS) indices, as traditional reliability measures of distribution system reliability, are calculated and compared. Fault analysis and its effects method is considered as a general scheme for these reliability analysis. Keywords: Fault Current Limiter, High Voltage Substation, Distribution System Reliability.