Because the Boussinesq equation is governing equation of an ideal fluid, a sea bottom friction and a wave breaking, which are the phenomena related to energy dispersion, cannot be handled precisely. A particle method on the basis of the Navier-Stokes equation is effective for numerical analysis of wave breaking with a splash. In this study, an Euler-Lagrange coupling for boundary interface between the Boussinesq equation model and the particle method are proposed. As basic studies to build a multi-purpose numerical wave basin, a wave motion in a wave flume is simulated by the present coupling model. Agreement of predicted water surface profiles by both models in the vicinity of a boundary interface is confirmed.