Abstract: The transducer is one of the core components in the therapeutic ultrasound system, and its impedance and driving power are important for the safety and efficacy of ultrasound therapy. A device based on voltage-current conversion circuit and data acquisition card is developed. This device is used to measure the phase, impedance and power of the 1.36 MHz and 3 MHz transducers at the driving signal with different voltages. The measurement results are compared with the results measured by using the voltage-current probes and the power component of the oscilloscope and by the commercial power meter. It is shown that the relative errors of the amplitude and phase in impedance measurement by this device are respectively within ±2 Ω and within ±2°. In addition, the errors of the incident power and active power are less than 5%. The results demonstrate the capability of the developed device for real-time measurement of the impedance and driving power of therapeutic ultrasound transducer.