The released nit rogen and phosphorus by surface runoff from uplands in the Taihu Lake catchment were investigated in a case study. Results showed that each year

about 12.66 kg/hm2 of nit rogen and 4.05 kg/ hm2 of phosphorus from the uplands in the catchment were discharged into water body

accounting for 5.6% and 4.1% of annual fertilization

respectively. About 3.86 t of total nitrogen and 1.24 t of total phosphorus f rom the uplands in the demonst ration area were discharged into water body per year. Nit rate —N and PN were the main component part of N loss

which indicates that controlling Nit rate —N and PN loss is the key to controlling non-point pollu-tion. PP was the main component part of phosphorus loss

accounting for 76 % of total phosphorus. Nitrogen and phosphorus loss were obviously characterized by seasonal variation. Summer and autumn were the high load sea- sons

in which nit rogen and phosphorus loss fromJune to November accounted for 83.35 % and 79.79 %of total loads

respectively.We should pay great attention to controlling nutrient loss during farming for non-point pollution control.