Abstract: Based on the method of Green's function, the problem ofSH-wave scattering by interface radial cracks with arbitrary finite lengthson a circular cavity in piezoelectric bimaterials was investigated in thepresent paper, and the solution of dynamic stress intensity factor at thecrack tip was given. Firstly, a pair of coupled Green functions on theelastic displacement and the electric potential which were suitable for thepresent problem was constructed. Secondly, the infinite piezoelectricbimaterials were divided into two semi-infinite media. Based on thecrack-division technique and the continiuty condition at the interface, twohalf spaces were bonded to infinite whole space. Thirdly, integral equationsfor the solution of the unknown stresses, which were related to dynamicstress intensity factor at the crack tip, were established. Finally, someexamples and results for dynamic stress intensity factor (DSIF) of theradial cracks on a circular cavity were given, and the influence of acircular cavity on DSIFs at the crack tip was discussed.