Erosion behavior of soft cohesive sediment deposits has been investigated in laboratory experiments. Such deposits are representative of the top, active layer of estuarial beds. An experimental procedure involving layer by layer erosion under a range of bed shear stresses, Tau sub b, of successively increasing magnitude was utilized. Interpretation of the resulting concentration-time data together with bed density profiles yielded a description of the variation of the bed shear strength, Tau sub s, with depth as well as an expression for the rate of surface erosion. In general, Tau sub s, increased with depth and also was influenced by the type of sediment, bed consolidation period and salinity. The rate of erosion was found to vary exponentially with (tau sub b-tau sub s)1/2. In modeling estuarial bed erosion, it is essential to take these characteristics of tau sub s and the rate of erosion into account.