Abstract: According to the present disclosure, provided is a method for determining phase transition temperature using electrical conductivity. More specifically, according to the present disclosure, there is provided a method for determining phase transition temperature using electrical conductivity, including preparing a graph of the change in electrical conductivity of molten salts according to temperature, and performing at least one mathematical analysis of (i) performing a first-order differential on the graph, (ii) performing a second-order differential on the graph; and (iii) determining the number (n) of data and resolution (AT) based on the graph to derive Tn by Equation (1) below and performing linear regression analysis on a linear section to detect an outlier based on a distance from the linear regression equation, T n = T max - ? ? T × n Equation ? ( 1 ) where n denotes the number of data, and ?T denotes an interval of measurement temperature and means resolution.