Abstract: There are many instances where the dynamic fracture events are the results of fluid pressure acting on the structures. This paper describes the development of integrated fluid/structure/fracture computational program, PFRAC (Pipeline FRacture Analysis Code), and the applications of this code in the dynamic crack propagation for gas pipelines. It also discusses the conditions of crack initiation, propagation and arrest. For the calculation of the crack driving force, G, in PFRAC, the numerical approach using the nodal force release and the energy balance methods are described. Based on the test data, a linear decay function of the internal gas pressure behind the crack tip, is incorporated into PFRAC program.