Abstract: A 3-D baroclinic ocean model is used to examine the influence of tide, offshore wind and upwelling-favorable wind on river plume development. Both tidal mixing and wind stirring can weaken the vertical stratification induced by freshwater buoyancy, but different mechanism dominates such a process: tidal mixing is accomplished through the upward dissipation of turbulent kinetic energy whereas wind stirring is in the opposite direction. By simulating river plume evolution under the combined action of tide and estival wind field averaged over many years, it is found that the modeled salinity distribution is consistent with observed rather well, which means river plume development plays an important role in adjusting the salinity distribution in surface layer of Bohai Sea.