The hydrolysis and polymerization of polyferric sulfate (PFS) were characterized. Jar test experiments were conducted to evaluate the coagulations of PFS, ferric chloride, and polyaluminum chloride. A pilot water-treatment plant consisting of coagulation, sedimentation, and filtration processes at a capacity of 30 1/h was simulated to analyze the effect of coagulant types on their performances. Results show that PFS leaves less iron residual and yields more efficient removals of turbidity and color than equivalent doses of conventional coagulants.