In numerical simulation, the bow flare slamming phenomenon is often treated as the wedge impact to water surface. Up to now, in many numerical simulation, the impact pressure under bow flare slamming has been firstly calculated by CFD in which the structure have been assumed to be rigid, and then the structural response has been calculated utilizing FEA under the pressure obtained by CFD. But, the impact pressure is possible to be influenced by the structural rigidity. In this paper, in order to establish the assessment procedure of the structural response under bow flare slamming load, the general purpose FEM software; LS-DYNA, which can simulate the structure-fluid coupling behavior by ALE, is applied for the impact problem of elastic wedge. The parametric calculations are performed to obtain the pressure and the structural response by changing the velocity and the attacking angle of wedge to water surface. And, the effect of the structural rigidity on the impact load and the structural response are investigated by series of calculations.