A measuring system for determining the electromechanical coupling characteristics of a piezoceramic (PZT) vibrator, which apply photo-interrupters matrix, glass tube, and metal ball to measure the bouncing motion, wherein the system includes an elastic-bouncing tester, a height measuring circuit, an instantaneous height indicator, a microprocessor, a monitor, and a driving circuit. There is a metal ball in the elastic-bouncing tester. By measuring the bouncing height and flying time, it can determine the electromechanical coupling characteristics of a PZT vibrator or the hardness of other rigid objects.