Ultrafiltration (UF) membranes are commonly confronted with threats from pollutants during long-termoperation. The zwitterions with high hydrophilicity are expected to be the critical material to improve theanti-fouling and antibacterial abilities of membranes. Herein, a new zwitterionic polyethersulfone (PES)(zwitterionic PES - ZPES) was synthesized. The as-prepared ZPES was used to fabricate a zwitterionic UFmembrane via the non-solvent induced phase inversion (NIPS) method. Zwitterionic polymer skeletonenhanced the hydrophilicity, permeability and anti-fouling properties of the material. As a result, theZPES membrane exhibited doubled water flux growth (269.6 Lm2h1) compared with that of the PES(125.3 Lm2h1) and high protein rejection (98.6%). Besides, the ZPES membrane could maintain anexcellent flux recovery rate (94.1%) and antibacterial effect (more than 95%). Therefore, the excellentanti-fouling and antibacterial abilities of the ZPES membrane broaden its application scope further.