Abstract: In this paper, the elastic-plastic dynamic response at the tip of semi-infinitecrack in the interface between two dissimilar orthotropic materials subjected to impact isinvestigated. By means of the integral transform, Wiener-Hopf technique and Cagniard-deHoop's inverting path,the analytic solution of the question is acquired,and then the dynamicintensity factor of the crack is also obtained. By using Dugdale mode,tWo relations areobtained.One is the extending velocity of its plastic domain with the propaga...