An　Ag-N-codoped　TiO2　photocatalyst　was　prepared　by　a　new　sol-gel　hydrothermal　method　and　its　morphology,　structure　and　elemental　composition　were　characterized　by　X-ray　diffraction(XRD),　scanning　electron　microscopy(SEM),　transmission　electron　microscopy(TEM)　and　infrared　spectroscopy(IR).　Meanwhile,　the　antibacterial　activity　on　Escherichia　coli　of　Ag-N-TiO2　was　also　studied.　The　synthesized　Ag-N-TiO2　photocatalyst　displayed　good　crystal　structure　with　high　crystallinity,　uniform　dispersion　and　nano-order-scale　size(diameter　was　about　11.32　nm).　Furthermore,　it　showed　high　antibacterial　activity　against　Escherichia　coli,　with　an　average　diameter　of　the　antibacterial　halo　of　15.2　mm　and　14.7　mm　in　visible　light　and　dark　conditions,　respectively.　SEM　images　revealed　that　the　surface　of　bacterial　cells　became　sunken,　corrugated,　and　perforated,　and　that　the　flagella　were　lost.　Therefore,　the　Ag-N-TiO2　photocatalyst　has　the　potential　for　use　in　the　disinfection　of　drinking　water.　©　2016,　Science　Press.　All　right　reserved.