Abstract: Zwitterionic copolymers are generally considered to be applied in nonfouling applications to prevent nonspecific protein adsorption as well as to minimize bacterial or mammalian cell adhesion and the research takes advantage of zwitterionic copolymers in film materials. Firstly, 4-vinyl pyridine (4-VP) reacted with 2-(dimethylamino)ethyl methacrylate (DMAEMA) by radical copolymerization to prepare P(4-VP-co-DMAEMA) with different copolymerization ratios. Then, the quaternary amination modification of P(4-VP-co-DMAEMA) was implemented by different amounts of 1, 3-propanesultone to obtain functional zwitterionic copolymer P(4-VPPS-co-DMAPS) with different ionization degrees. The chemical structures of P(4-VP-co-DMAEMA) and P(4-VPPS-co-DMAPS) were characterized and analyzed by Fourier Transform Infrared Spectrum (FT-IR), Nuclear Magnetic Resonance Hydrogen (¹H-NMR) and Gel Permeation Chromatography (GPC). The mechanical property, thermal property and antibacterial/antifouling performances of P(4-VP-co-DMAEMA) and P(4-VPPS-co-DMAPS) were tested and analyzed by universal tensile testing machine, Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TG), dilution coated plate method and optical microscope. Effects of molar quantity ratio of monomer unit and ionization degree of zwitterionic copolymer P(4-VPPS-co-DMAPS) on the physical, chemical performances and functionalities of P(4-VPPS-co-DMAPS) were also studied. When the real molar ratio (n_4-VP/n_DMAEMA) in P(4-VP-co-DMAEMA) was about 1, the elongation at break was about 350% and breaking strength was 6 MPa, which was applicable to film materials. Although the high ionization degrees was helpful to antibacterial and antifouling ability of P(4-VPPS-co-DMAPS). If the ionization degree of P(4-VPPS-co-DMAPS) was high, the film was easy to absorb water, which led to bad mechanical property and limited their application. It was important to balance antibacterial, antifouling ability with good mechanical property of P(4-VPPS-co-DMAPS). The results showed that the best film (P(4-VPPS-co-DMAPS)-2/20%), exhibited proper thermal stability (T_d=245℃), elongation at break (25%) and breaking strength (17.5 MPa). Moreover, P(4-VPPS-co-DMAPS)-2/20% possessed excellent sterilization and anti-adhesion properties, which would be applied in antibacterial materials in the future.