Abstract: In this paper, total nitrogen is determined as the main pollutant for total quantity control in the coastal area of Bohai Sea in Shandong province. The total quantity of land-based pollutants into the sea is evaluated by using the output coefficient method, and the source and spatial-temporal distribution pattern of land-based pollutants into the sea are clarified. Combined with the coastal water quality target, the allowable inflow of 12 main rivers is calculated to be 86,184 tons/year by using the optimization method of sea load. In order to achieve the water quality goal of Bohai Sea pollution control, it is necessary to reduce the emission by 60,505 tons/year. Plan the land and sea as a whole, the total nitrogen reduction of cities in the study area was allocated. This study has important reference value for effectively improving the environmental quality of Bohai Coastal Waters in Shandong province.