Abstract: The muddy coast is an important part of China′s coast, and the wave-lifted sand and tide-transported sand are the main forms of sediment movement along the muddy coast. The sediment concentration is rapidly going up during heavy storm waves. The high sediment concentration can cause terrible sediment back-silting within the ports and waterways. In the past, the experimental studies mainly focused on sand and silt concentration under breaking waves. In this study, wave-current flume test studies are carried out for the distribution characteristics of the sediment concentration and mechanism of lifted sand under spilling waves action, in which the gentle slope (1:200) is set up for testing wave movement. The distribution characteristics of the mud concentration having mud density of 1.35,1.40,1.45 kg/L and mechanism of the wave-lifted sand by the action of the spilling waves have been analyzed respectively through the flume tests. The mud for model tests is taken from the trial excavating channel for the Xuwei waterway. Research results show that the capacity of the breaking wave-lifted sand and the mud density have the strong nonlinear relationships. And the bottom becomes a high sediment concentration area beyond the wave breaking point, the sediment concentration is up to the maximum around the wave breaking point, and there is water stratification behind a certain distance when mud density is less than 1.45 kg/L. When there is a greater sediment concentration in the bottom, the vertical distribution characteristics of both mud and silt concentration are nonuniform under the breaking waves action.