This study concerns a new application of the Bond graph to the analysis of dynamic behavior in a turbomachinery system. A theoretical and experimental study has been made on the transient characteristics of a centrifugal pump during the starting/stopping periods. Instantaneous rotational speed, torque, flow rate and total pressure rise are measured in the experiment. Theoretical calculations for the prediction of transient characteristics using the Bond graph, which is a one-dimensional analysis of the system dynamics based on energy conservation, are developed and the results are compared with the corresponding experimental results. It was clarified that the results of Bond graph simulation agree well with the experimental results, and that Bond graph simulation is very useful for predicting the pump transient characteristics during starting/stopping periods.