ABSTRACTIn this paper, wave transformation over a submerged reef has been numerically studied based on the OpenFOAM model. This numerical model solves the Reynolds-Averaged Navier-Stokes equations for two-phase flow and employs the volume of fluids (VOF) method for the free surface. The k-ω SST turbulence model is used to simulate wave breaking, and the wave generation library waves2Foam is adopted to generate waves in the model. The numerical model is first validated against the physical experimental data, and it is shown that the model is capable of simulating the key processes of wave shoaling, breaking and transmission over the submerged reef. Then, a series of numerical tests are conducted considering different incident wave heights, submergences and slopes of the reef. The influences of reef slope and submergence on the wave properties over the reef are discussed, which include the wave reflection and transmission coefficients, breaking wave height, wave-induced setup, and energy dissipation.