A　novel　antibacterial　polyacrylonitrile　(PAN)　membrane　covalently　immobilized　with　lysozyme　was　prepared.　First,　the　virginal　PAN　membranes　were　prepared　via　the　classic　immersion　precipitation　method.　After　modification　with　NaOH,　HCl,　ethylenediamine　(EDA),　the　lysozyme　was　covalently　immobilized　onto　the　surface　of　the　PAN　membranes　by　glutaraldehyde.　The　chemical　compositions　of　virginal　and　modified　membranes　were　characterized　by　Fourier　transform　infrared　spectroscopy　(FT-IR)　and　Energy　Dispersion　X-ray　(EDX).　The　morphology　and　performance　of　the　immobilized　membranes　were　characterized　by　Scanning　Electronic　Microscopy　(SEM),　filtration　performance　measurements,　the　amount　of　bonded　lysozyme,　lysozyme　activity　measurement　and　flow　cytometry　method.　The　antibacterial　tests　confirmed　that　the　immobilized　lysozyme　membrane　displayed　an　excellent　antibacterial　performance　against　Staphylococcus　aureus　(S.　aureus).　©　The　Royal　Society　of　Chemistry.