Abstract: An estimation method to calculate the pollutant load into sea from point sources (industrial wastewater and domestic wastewater) and non-point sources (agricultural land runoff and livestock industry) for coastal area has been constructed using statistical data.Pollutant load from each sub-region has been divided into several rivers based on geographic information.And attenuation coefficients have also been adopted to calculate the pollutant load into sea for each river.These coefficients represent the decay of pollutants from their origin to sea.The method was applied to calculate total nitrogen (TN) and total phosphorus (TP) load into sea from Tianjin from 2000 to 2014.The results show that:annual-mean TN and TP load into sea are 9 940.7 t and 663.4 t respectively; in 2012 both TN and TP flux into sea reach the maximum, which are 12 304.1 t and 830.0 t respectively; in 2000 both TN and TP flux into sea are minimum, which are 7 604.1 t and 494.0 t; the pollutant load into sea through Yongdingxin river occupy the largest proportion of the whole pollutant load into sea from Tianjin; agricultural land runoff and livestock industry take up most of TP load into sea while TN load into sea from each source is very close with each other; pollutant load into sea from each sub-region synthetically reflects factors such as population, economic development and pollution abatement.To protect the nearshore environment of Tianjin, industrial wastewater pollution from Binhai New District, domestic wastewater pollution from Haihe river and agricultural land runoff and livestock industry pollution from Yongdingxin river should be controlled mainly to reduce pollutant load into sea.