Rapid socio-economic development in Xiamen has been deteriorating the marine environmental quality for years.Thus,its internal requirement to control the land -based pollution so as to improve the marine environmental carrying capacity.The approach for this study was "Strategic Planning-Scenario Analysis- Numerical Modeling".With the result of numerical modeling,sharing portions of point source pollution (PSP),non-point source pollution (NPSP) and Jiulong River input were identified.Then four scenarios were set up for further analysis.