During the transition between these two stages, there was an abrupt change of the settling velocity. Time-dependent settling velocity was then described with functions obtained from regression analysis, which showed a linearly decreasing settling velocity during the first stage and an exponential decreasing trend during the second stage. The influence of tube diameter variation was negligible on the mud settling process, while the tube length had significant influence on the transition pattern between two stages. Mud concentration played an important role in the flocculation formulation, and finally dominated the settling velocity of the cohesive sediment. It led to a distinguished peak value of the settling velocity corresponding to an initial sediment concentration of 20kg/m3. Salinity also exhibited obvious impact at the beginning stage of the settling, which presented a lowest settling velocity corresponding to a salinity of 15% for 50kg/m3 mud samples.