In the design process of electronic equipment, the early estimation of component temperature is of great importance. In order to predict the lifetime of equipments, the electrolytic capacitor is one of the most important components in thermal analysis of electronic equipment. To predict the component and system temperature, the thermal flow simulation technique has been applying to thermal design in the development phase of electronic equipment. In this study, we investigate the compact thermal modeling method of electrolytic capacitors. This paper describes the result of experiment of the confirmation of the main thermal path of the electrolytic capacitor on the printed circuit board as the basic data for the investigation of modeling method. In addition, based on the result of the experiment, we considered the benchmark experiment procedure.