A gas turbulence-solid turbulence model (k-epsilon-Theta -k(p)) was used to simulate the hydrodynamics in the entrance region of a downer. This model incorporates a k-epsilon turbulence model for gas phase, a It, turbulence model and a kinetic theory description of solid stresses characterized by granular temperature (Theta) for solid phase. The predicted profiles of local solids fraction and particle velocity have good agreement with the experimental data in a wide range of solids fraction. The solid pressure has a large gradient in the inlet region, which becomes a main driving force for the particles to move from the center to the wall. The sensitivity analysis shows that the inlet granular temperature has a large influence on the predicted results. Over the whole flow field, a clear relationship between the diffusion coefficient of particles and the local solids fraction is found, that is, a smaller solids fraction corresponds to a larger diffusion coefficient.