To provide an active damping performance evaluation system capable of evaluating accurately damping performance of a damping object without being affected by a difference of a vibration mode.

In a damping device 1 having a sensor 2 for detecting vibration of the damping object 9, an actuator 3 for exciting the damping object, and an active damping control means 11 for outputting an excitation signal of the damping object 9 to the actuator 3 corresponding to a signal of the sensor 2, a disturbance signal superimposition means 21 for superimposing a disturbance signal Aif on an excitation signal of the control means 11, while sweeping a frequency, is connected between the control means 11 and the actuator 3, and an amplitude ratio detection means 23 for detecting an amplitude ratio Arf (=Aof/Aif) classified by frequency of a sensor detection signal Aof to the disturbance signal Aif is connected between the control means 11 and the sensor 2, and while stopping or starting the control means 11, damping performance of the control means 11 is evaluated by a difference between an amplitude ratio Arfn classified by frequency at a stopping time and an amplitude ratio Arfc classified by frequency at a starting time by an evaluation means 22 connected to the control means 11.