Abstract: This paper proposes an explicit met hod for analyzing the dynalnical re-sponse of the contactable cracks with friction in the crack surface,The method can be usednot only to simulate the process of impaict of the crack surfaces,but also to consider theeffects of static and kinematic frictional resistance when contact-slip of crack surface occurs. Dynamical contact of an infinite crack and scattering of P wave by a contactable crack inhalf-space are calculated.The results indicate that the method in the pape...