Abstract: Based on different water quality requirements of marine functional areas, the research method and technical route of marine environmental quality control objective (MEQCO) were made.The control sea area was divided into priority control area, key control area and general control area.The dominant pollutants in different control areas were screened, and then the MEQCO was proposed.Take Bohai Sea area in 2010 as an example, the research method of MEQCO was demonstrated.Result showed that the method was feasible and could propose the MEQCO of Bohai Sea area scientifically.It could provide technical support in making policy for the marine administrative department.