The flocculation effect of poly aluminum ferric chloride (PAFC), diatomit and poly(dimethyldiallyl ammonium chloride) (HCA) which was used alone or cooperated with each other, on the water treatment of the urban landscape waters in Cangzhou was studied. The effect factors included the dosage and proportion of flocculent, the pH and sedimentation time. The experiment results showed that the effect of PAFC cooperating with diatomit or HCA was better than that of the single one. The optimum mass concentration ratio of PAFC to diatomit was 1: 4, a lower mass concentration benefited the removal of turbidity. The turbidity removal effect of PAFC+HCA is the best, with the optimum mass concentration of PAFC 35mg/L, HCA 0.5mg/L ,the best pH=8~9 and the sedimentation time of 1.5 hour, the removal ratio of turbidity was as high as 94%.