Abstract: The scattering of SH-wave by the circular cavity near the bimaterial interface in a vertical half-space and dynamic stress concentration were explored based on the complex function method and the Greens function method. The solution of the present problem was given by the image method. Firstly, a suitable Greens function was constructed, which was the essential solution of displacement field for an elastic right-angle plane with a circular cavity subjected to anti-plane harmonic line source loading at the horizontal surface. Secondly, the conjunction method was used to develop the scattering model of SH-wave, then a series of Fredholm integral equations of the first kind for determining the unknown forces were established through the continuity conditions expressed in terms of the Greens function. Finally, the dynamic stress concentration was analyzed by numerical examples.The numerical examples show that the dynamic stress concentration depends on the incident frequency and angle of SH-wave, the geometrical position of the circular cavity, and the different media combination parameters. Compared with the scattering of SH-wave by the circular cavity in a complete space, the free boundary of the vertical half-space has great effect on the incident plane SH-wave and the dynamic stress concentration factors around the circular cavity are magnified obviously while the SH-wave disturbs from a rigid medium to a soft medium.