Based on the collection data of position and concentration of pollution sources in spring,mainly considering the concentration level of DIN,DIP and chlorophyll-a,the current and water quality coupling numberical simulation was carried out.Taking into account baroclinic water,MIKE21 model was used before and after the Land-making Project in the Oujiang Estuary.The result shows that the project would not cause great changes to the hydrodynamic characteristics in Wenzhou Bay,but it would increase the current speed in the north area and decrease the current speed in the south area near the estuary.The salt distribution in the north area changes obviously while the amount of salinity increases near the north part of the estuary.Generally,Phrase I and Phrase II projects would not cause large scale changes to the seawater quality around,but it does have a certain effect on the local seawater quality.Nutrients and chlorophyll-a near the mouth of the estuary showed a rising trend and the eutrophication was aggravated.