Load rejection is the most unfavorable working condition for the civil structure of pumped storage unit. Grasping the impact of the load rejection condition on the civil structure of the unit is very important. This paper introduces the automatic monitoring results of the prototype monitoring instrument buried in the civil structure of the unit in the process of load rejection test

indicating that the civil structure of the unit works well in a good flexible state. The data in this paper are the first-hand measured data in the process of the load rejection

which is summarized to be used as a reference for similar projects.