Abstract: The influence of structural and viscous damping on vibratory response was investigated during vibratory stress relieving process (VSR) of complicated components.The "几"-like dynamic curves obtained with continuous frequency scanning method during VSRP were also explained.It was shown that the structural changes of sympathetic vibration curves were dependent on comprehensive effectiveness of structural ngidity,structural and viscous damping of the components.Because it is the ultimate purpose to realize dimensional stability, decrease or homogenize residual stress by VSR, a new criterion is then put forward to evaluate effectiveness of a vibratory stress relieving process.According to this criterion,the smooth of the scanning curves is an evaluation on the effective ness of the results of VSR.