Total nitrogen discharged from different sources in Taihu Lake area of.Jangsu province in 1997 is estimated as 64824t.Proportion of total nitrogen discharged into Taihu Lake area water system of Jiangsu Province from different sources in this area is 24% from farmland, 22% from industry, 18% from human manure and urine, 16% from animal & poultry manure and urine, 14% from life waste water, and 6% from carefully rasied fish pond.Nitrogen amount discharged from field, animal husbandry and fishery targets 46% of total nitrogen into the water, which shows that nitrogen pollution from agriculture production is serious.Proportions of COD_cr discharge from different sources are shown in detail 89385 t°a^-1 from life waste water, 74551 t°a^-1 from human manure and urine, 16820 t°a^-1 from animal & poultry manure and urine, 2758.5t°a^-1 from carefully raised fish pond and TP (total phosphorus) is 7241°a^-1 from animal& poultry manure and urine, 2239t°a^-1 from life waste water, 1969t °a^-1 from human manure and urine, 407.3t°a^-1 from carefully raised fish pond.Results of equivalent standard polluting load analysis show that the cosequence of worsening water quality is resulted from TP, TN and COD_cr in life waste water, human manure and urine, animal& poultry manure and urine and carefully raised fish pond.