The principle included in construction of submerged breakwater is to protect beach from morphological changes and the sediment transport against incoming waves. In the present study, boundary element method (BEM) is employed for solving the scattering problem of incident wave passing the vertical and inclined submerged breakwaters with rigid boundaries. The boundary element integral equation with constant and linear elements is used to solve the Laplace equation (for the incompressible fluids) in boundary value problems by development of a FORTRAN computer program. The diffraction of water waves has been investigated in floating and submerged breakwaters so that to gain this goal, a parametric study on the water wave reflection and transmission coefficients and the water surface elevation has been performed considering the influence of various sea states such as wave number, obliquely of waves and wave stippness, and several structural configurations such as width, depth and angle of inclination.