Abstract: Guided waves have been utilized in various manners for non-destructive evaluation and testing.Due to the dispersive and multi-mode characteristics of guided waves,the pulse of energy will spread out in space and time as it propagates.For long-range guided waves inspection application,it constrains the choice of operating point to regions on the dispersion curves where dispersion effect is relatively small.Based on the knowledge of the guided waves propagation in time-space,a space model is established to compensate the dispersion in long range guided wave testing.Consequently,the characteristics of structure,such as the length of structure or the position of defect,can be obtained directly,and the resolution of detection can be improved.It is shown that the technique can improve and extend the effect of guided waves for NDT methods.