In this paper, energy consumption and variation factors in Niigata University are analyzed. First, in order to grasp the energy consumption level of Niigata Univ., energy consumption is analysed for Niigata Univ. and other national universities. Energy consumption is compared with national universities in Japan. Second, primary energy consumption in Niigata Univ. is analysed in 2002-2017. In particular, a detailed analysis on the power consumption of each system is performed. As a result, it became clear that the power consumption of equipment operating around the clock accounted for a large percentage of the annual power consumption.