Internet of Thing becomes a advanced technology in transforming many areas of mod-ern age including power system. Electricity is also a backbone of the country?s economy and it is important to get the reliable supply at all time. Using IoT technology, the switching time and restoration of the system can be reduced and consequently the reliability can be improved. In this paper, how to concern the IoT technology in power system is described. Moreover, the reliability improvement by IoT technology is also conducted with the reliability indices analysis. According to the results, the amount of energy not supply, ENS and system average interruption duration is reduced by the IoT technology. The reliability test system of RBTS bus 2 is used as the test system.