The removal of water pollutants and the pollution of membrane were observed by advanced treatment of ultra filtration(UF) and inline coagu-flocculation-UF(ICUF) with different amount of coagulant and slightly polluted water as raw water.It was shown that the effluent quality of combination process,with its turbidity below 0.1 NTU and the CODMn average removal rate 33%,was better than UF's after 150h operation.It was also shown that the inline coagu-flocculation could retard membrane pollution since the growth of transmembrane pressure in ICUF was more slowly than UF's and the membrane pollution in ICUF could be removed.The UF effect would be improved with the amount of coagulant increased,but if the costs were considered,the optimal coagulant dosage was 30 mg/L.