An adaptive shunt system for controlling vibrations of a frequency-varying structure, the system comprising: a detector for detecting vibrations generated from a predetermined structure and generating vibration signals corresponding to the vibrations; a computer for inputting the vibrations signals from the detector; a signal processing unit for processing the vibration signals from the computer and generating a voltage command in real-time; and an adaptive shunt device for adaptively controlling the vibrations of the structure of which natural frequency varies at every moment according to the voltage command.