Abstract: Response surface methodology(RSM) was applied to analyze the magnetic flocculation influencing factors and removal efficiency for micro-polluted river water treatment.Box-Behnken experimental design was applied.The poly aluminum chloride(PAC),magnetic particle(MP) and polyacrylamide(PAM) were chosen as causal factors.The effects of these factors on turbidity,orthophosphate(PO₄^3--P) and chemical oxygen demand(COD) removal efficiency were analyzed using RSM.The pollutants removals in river water were developed to describe by regression models.The results showed that the optimum conditions were PAC 51.31 mg/L,magnetic particle 176.47 mg/L and PAM 0.10 mg/L.Based on these conditions,the turbidity,orthophosphate and COD removals were 96.80%,86.25% and 51.00%,respectively.The relative errors between the measured data and the predicted values were less than 2.12%.It confirms that the statistic models are reliable,and the magnetic flocculation operating conditions for contaminants removals in river water are appropriated.