Abstract: Based on the LOADEST model, the multivariate linear regression equations of the total nitrogen (TN) and total phosphorus (TP) fluxes were constructed by using the daily flow and discrete water quality data at the Haihe sluice in 2013-2015.The equations were evaluated and the determination coefficient (R²) of TN and TP models were 0.917 and 0.924 respectively, which proved the LOADEST model is suitable for the evaluation of the pollutant fluxes into the sea from the sluice-controlled river in the plain urban area.The assessment results also indicated that the fluxes and water quality of the TN and TP showed different variation characteristics.In 2013-2015, the average monthly concentration of the TN varied from 3.38~8.33 mg/L, the concentration in the flood season (June-October) was lower than the non-flood season.The monthly average concentration of the TP was 0.17-0.88mg/L, and the concentration in the flood season was higher than the non-flood season.The annual average flux of the TN was 2200t, the flood season accounted for 43.7%; the daily average flux was 25.8 t, this value in the non-flood season was twice as in the flood season.The annual average flux of the TP was 216 t, the flux in the flood season accounted for 69.3%; the daily average flux was 2.5 t, this value in the flood season was normally higher than the non-flood season, the highest daily average value was in September, and the lowest value was in April.The results of this paper can provide a scientific basis for the total maximum daily loads (TMDL) control implemented for both land and sea.