The impedance characteristics of piezoelectric vibrator form the basis for the analysis of ultrasonic motor models and the design of driving controller. Currently, most of the impedance characteristic testing of ultrasonic motors is conducted under low-voltage conditions, while the operating voltage of ultrasonic motors ranges from tens of volts to hundreds of volts. The impedance characteristics of the motor also vary under different excitation voltages. Therefore, a testing system capable of measuring the impedance characteristics of ultrasonic motors under high-voltage conditions was constructed using LabVIEW and NI virtual instrument. In the experiment, the impedance characteristics of the stator under different excitation voltages was tested, and parameters of the equivalent circuit were then identified. This research lays the foundation for the further investigation on the analysis of ultrasonic motor models and the adjustment of control strategies.