The high waves of Typhoon No. 18 that hit Japan in 2004 are reported to have destroyed the joints between the parapet and main body of a revetment built along the coast of Hiroshima Port. At the time of the typhoon, the high waves were compounded by the coincidentally high tide level and there is a possibility that impact wave pressure was generated against the leaning revetment. The effect of impact wave pressure on the stress on parts is known to vary because the duration of its action is short but its response characteristics to the impact force are unknown. Accordingly, a large-scale destruction and deformation experiment was conducted for this research to study the relationship between the joints of a leaning revetment and the impact wave pressure. First, the wave pressure working on the leaning revetment was measured and the generation of impact wave pressure was confirmed. Then, the shear stress intensity and tensile stress intensity working on the joint bar, calculated from the maximum wave pressure including impact wave pressure, were compared with the mechanical properties of the joint bar. The tensile stress intensity, which was greater, was used as a reference to make an experimental model. A strain gauge was fitted to the surface of the joint of the experimental model so as to judge whether or not the joint was destroyed. The results of the destruction and deformation experiment confirmed that there was impact wave pressure and that cracks were generated in the joint. The tensile stress intensity working on the joint, calculated based on the maximum wave pressure at the time of the crack generation, was higher than the tensile strength of the joint, which was found not to have been fractured.