High-speed trains consume huge electrical energy to run at maximum speed. It is important to measure and analyze accurately the energy consumed during the commercial operation for the energy saving. But there are few studies that report experimental results. This paper presents the measurement results of consumption energy for Korean high-speed trains on the commercial operation conditions and the analysis results in relation to running section and running speed, etc. For this study, the power input to vehicles is measured with the vehicle speed, the powering/braking command and the running time.