The main purpose of this thesis is to study the emergency power-supply system analysis for red and orange lines of Kaohsiung Mass Rapid Transit(KMRT). First of all, the configurations of KMRT power-supply were introduced. Then the traction power required and station substation demand were analyzed by computer program. The suitability of planning and the power-supply system were examined by considering their target year requirements based on the headways of both 2 and 3 minutes. The dispatch strategic is investigated when one of Bulk Supply Substation(BSS) was outaged. To analyze the system transient stability for the islanding operation of KMRT system when all 161kV circuits tripped, the mathematical models of the standby diesel generators with excitation system and governor system as well as the loads are considered in the computer simulation. The Ferranti effect due to 22.8kV cables for the transmission of energy backup power to send the critical loads in the train station is investigated, it is found that the shunt reactors is required for the mitigation of over voltage problem introduced by the Ferranti effect.