To endow microporous polypropylene membrane (MPPM) antimicrobial capability, a versatile method was developed to quaternize MPPM surface. Firstly, acrylic acid (AA) was grafted on the MPPM surface via UV irradiation, and subsequent chemical binding of polyethyleneimine(PEI) by activation of carbodiimide. Then, the primary and secondary amine groups on macromolecular chains of PEI were tertiary aminated with propylene epoxide. The surface of MPPM was quaternized by the reaction between tertiary amine of PEI and benzyl chloride. Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), fluorescein disodium salt coloration and static water contact angle were used to characterize the quaternized membranes. The antibacterial capabilities of the quaternized membranes for E. coli and S. aureus were investigated via plate counting method. The results indicated that the quaternized membranes exhibited strong antimicrobial capability for both E. coli and S. aureus, and antimicrobial capability can be enhanced by increasing the density of positive charge on the surface of quaternized membranes or contact time.