The mean suspended sediment concentration (SSC) is one of the fundamental issues for engineering practice and numerical modelling. The parameterization of the SSC profile of silty sediment is still under‐researched. This chapter focuses on the mean SSC profile and the depth‐averaged concentration for silty sediment under non‐breaking wave‐dominated conditions. Firstly, the time‐averaged diffusion equation for suspended sediment transport was analytically solved based on assumed distribution of sediment diffusivity, and the expressions for the mean SSC profile were derived. Secondly, the formula for the depth‐averaged sediment concentration under wave conditions was yielded by integrating the SSC profile. The expression involves some basic physical processes, including the effects of bed forms, stratification and hindered settling. Verification using a number of experimental datasets showed that the proposed expressions can properly calculate the mean SSC for silt and are applicable for sand as well.