In this paper the dual boundary element formulation is developed to study crack surface contact problem with friction dynamic loads. The nonlinear three‐dimensional dynamic problem can be treated as linear problem by three assumptions. The dual boundary integral equations are given in the Laplace transform domain with the boundary varibles of displacement and traction on the external boundary and displacement discontinuities on the crack surface. Durbin's Laplace tranfrom inversion method is used and the dynamic stress intensity factors are determined by crack opening displacement. A rectangular bar containing a slant circular crack under a pressure Heaviside load is studied. The influrence of different elasticity waves on the dynamic stress intensity factorsKII(t) andKIII(t) are analysed in detail.