It is important to find out the load and source for the norrpoint source pollution about nitrogen and phosphorus in the runoff field of Yunlong reservoir in order to provide a scientific basis to protect water quality.The nitrogen and phosphorus pollution loads in Yunlong reservoir runoff field were estimated according to the approach of export coefficient modeling.The results showed that:(1)The total nitrogen and total phosphorus loads of norrpoint source in Yunlong reservoir runoff field were 2079.8 and 454.32 t/a respectively and the pollution loads in reservoir were 207.98 and 24.73 t/a respectively.(2)Nitrogen and phosphorus loads in Sayingpan town generated the highest volume

Yunlong and Maoshan town export were the lowest

and the remaining towns produced nearly.(3)The main pollutant sources were domestic pollutant and poultry excrement pollutant.