A series of indoor experiments were conducted to investigate the effects of different coagulants used single or combined with coagulant aids on removal of turbidity and decontamination of polluted water from Nanfei River, which will be further applied in coagulation and precipitation system of on-site construction for this river. Polymeric ferric chloride(PFC), polymeric ferric sulfate(PFS), polyaluminum chloride(PAC)and polyaluminum ferric chloride(PAFC)were selected as coagulants, and cationic polyacrylamide(CPAM), anionic polyacrylamide(APAM)and non-ionic polyacrylamide(NPAM)as coagulant aids. The results showed that four coagulants used only PAFC had high removal effect on turbidity, TP and COD_Mn, and did not affected the pH value of raw water, while the PFC and PFS which were used alone obviously reduced the pH value of raw water, Four coagulants which were used alone had little effect on removal of TN in water; The combined use of PAFC and CPAM has the best effect on turbidity, comparing to the effect of single use of PAFC, and their combined use with APAM; The combined uses of coagulants and CPAM enhanced the removal effect of turbidity and TP, but had few effects on the removal of COD_Mn, and their effects on the pH value of raw water and TN values were similar to their single use. PAFC+CPAM was selected as coagulant and coagulant aid for demonstrative project site of Nanfei River. their combined use achieved a stable treatment, and the turbidity and TP removal effect is good, the removal effect of turbidity and TP was 90% and 80% respectively; the removal rate of COD_Mn was about 52%; while the removal effect of TN was limited, the removal rate was only about 22. 4%.