Abstract: Currently the costal water pollution problem is more serious with the increase of waste discharge into inshore region. According to the characteristics of inshore regions with large scale of area,the rational grids distribution construction is important to improve computational enfficiency and precision for inshore regions. Based on the idea of the quadtree grid structure, the nested adaptive quadtree grids for the inshore water region is distributed according to demand of different research areas in this paper. The grid is densified scattered in the coastal pollution region,and the pollutant zone is focused to simulate. A numerical model is established by using the flux difference splitting(FDS)scheme of Godunov-type,and applied to simulation of flow and concentration fields for Haizhou Bay.Then the relationship curve between the waste discharge amount and the area of pollution zone is gained under the given condition of tidal range. The pollution control plan for cutting down waste discharge amount are obtained according to the limit area of pollution zone by environment protection department.