We present a numerical method combining the smoothed particle hydrodynamics (SPH) and discrete element method (DEM) to model liquid flows in the presence of solid particles. This approach does not require a computational mesh, nor does it rely on empirical models to couple the liquid and solid phases. In the present method, the SPH is applied to simulate the liquid flows, and the DEM together with interaction laws based on the theoretical contact mechanics is introduced into the SPH method to calculate the effects of contact between solid particles and between solid particles and walls. The introduced DEM model is verified by experimental analyses for the collapse of six solid cylinder layers. The proposed DEM SPH model is then applied to simulate the free falling of a rigid sphere in water with a free surface.