To produce high performance polymer microfiltration/ultrafiltration (MF/UF) membranes with lower production cost， the amphiphilic copolymers and their corresponding blend membrane were presented and investigated. A series of amphiphilic copolymers with different compositions and sequence structures were synthesized via living radical polymerization. The synthesized copolymers were blended into various membranes via phase inversion process. It was found that， during the phase inversion process， amphiphilic copolymer migrated spontaneously to the membrane surface， resulting the enrichment of hydrophilic components in surface layer. This hydrophilic layer provided the membranes with improved hydrophilicity and fouling resistance. Meanwhile， the better compatibility between polymer base and hydrophobic components prevented the loss of amphiphilic copolymers in real application of the blend membranes. Based on the fundamental in structures and properties of the blend membranes， large-scale preparation of amphiphilic polymers and corresponding MF/UF blend membranes were achieved. The produced blend microporous membranes have been widely used in various areas including water purification， wastewater treatment and medical filtering， etc.