Present study discusses the structures of flows with bed-load, suspended load and hyper-concentrated sediment load, and formulates their velocity profiles, thicknesses of bed-load layer and sediment concentrations. The entrainment velocity, which is employed in specifying the mixing process of density stratified flow, is introduced in evaluating the sediment transportation from bed load layer to the upper turbulent layer to formulate an equilibrium sediment concentration and the relative depth in between bed load layer and the upper layer. Such formulations realize that the mud flow process, which forms flows with a hyper sediment concentration, is explained successfully, using flume data which were carried out in 1990s.