No / The paper presents a 2-D large eddy simulation (LES) modelling approach to investigate the properties of the plunging waves. The numerical model is based on the smoothed particle hydrodynamics (SPH) method. SPH is a mesh-free Lagrangian particle approach which is capable of tracking the free surfaces of large deformation in an easy and accurate way. The Smagorinsky model is used as the turbulence model due to its simplicity and effectiveness. The proposed 2-D SPH-LES model is applied to a cnoidal wave breaking and plunging over a mild slope. The computations are in good agreement with the documented data. Especially the computed turbulence quantities under the breaking waves agree better with the experiments as compared with the numerical results obtained by using the k- model. The sensitivity analyses of the SPH-LES computations indicate that both the turbulence model and the spatial resolution play an important role in the model predictions and the contributions from the sub-particle scale (SPS) turbulence decrease with the particle size refinement.