As a substitute for microjet actuator, a buzzer is used to form microjet under water environment. The result is visualized by a high-speed camera which demonstrates the form and development of microjet. And its energy level is analyzed under a series of working conditions of the buzzer. The result shows that corresponding to the optimum working frequency, the energy of microjet can attain the highest level. The effect of microjet is also affected by the buzzer's driving signal waveform. The larger the factor of waveform's velocity change is, the higher the vortexenergy is, and the faster the microjet velocity is.