Structural materials used on system supplying energy must stand at high temperatures. The information about dependence of thermo-physical properties for those materials on temperatures is demanded to evaluate its heat resistance. So we develop a new method to measure thermo-physical properties using an infrared heating at high temperature. This technique uses a heat source to keep a temperature of sample as that to change the temperature. This report describes a comparison between analyses of heat conduction and experiment of that and dependence of time lag having relation to thermal diffusivity and changing temperature having relation to heat capacity on temperatures.