Three different water treatment ultrafiltration (UF) pilot plants were investigated to treat algae-rich reservoir water. Coagulation, coagulation-sedimentation and coagulation-sedimentation-filtration were applied prior to UF respectively. Based on the permeate water quality and the specific flux of UF, coagulation/settling process was selected as the best pretreatment method for UF membrane. Filter played a negative role in pretreatment for UF membrane fouling control.