Taking the river system in Suzhou City as our subject, during our 3-year wide-area points sampling, we chose dissolved oxygen(DO), Temperature(T), pH, Potassium permanganate index(COD_Mn), Sulfide(S^2-), Turbidity, Chlorophyll-a(Chl-a)and UV spectrophotometry(UV₂₅₄)as the water quality monitoring indicators. By analyzing the cumulative frequency distribution and trend among various indicators, we identified the pollutants with main apparent characteristic from different polluted water and divided types of water pollution according to that. The results show that value of UV₂₅₄, Turbidity/ρ(COD_Mn), ρ(S^2-)and ρ(Chl-a)can be used as features of pollutants because of their good distinguish degree; Different polluted water can be divided into four types: organic leading, inorganic leading, nutrition leading and hybrid, filter conditions of the former three types are value of UV₂₅₄·ρ(S^2-)·1 000>10 cm^-1·(mg·L^-1), Turbidity/ρ(COD_Mn)>15 NTU/(mg·L^-1), ρ(Chl-a)>20μg·L^-1; This method can identify different types of the six monitored rivers.