Abstract: The reclamation works placed on both sides of a river mouth will not only change the river topography and a dynamic environment but also have some influences on the pollutant transportation. Taking the Shawang River estuary situated in the Ganyu county of Lianyungang city, Jiangsu Province, as a case history, the pollutant transportation influenced by the reclamation works placed on both sides of a river mouth before and after construction of the reclamation works is calculated by a 2D convection-dispersion numerical model, and the influences of construction of the reclamation works on the polluted water transportation are analyzed in this paper. The results show that the reclamation works located on both sides of a river mouth may result in narrowing the flow passage and make the mouth extend towards the deep waters, which is favorable to the polluted water dilution and transportation in the deep waters by the action of stronger hydrodynamic force. Meanwhile, as the reclamation works have changed hydrodynamic force in the flow passage and the front, when the hydrodynamic force along the frond of the reclamation works goes weaker, such variation may be unfavorable to the pollutant transportation and dispersion in the waters. On the contrary, the reclamation works make the flow in the passage and the front increase, which would be advantageous to the pollutant transportation in the waters. The numerical calculation results can provide a reference for assessment of the environment impacts given by the reclamation works located at the river mouth.