New　types　of　visible-light-driven　photocatalysts　with　high　activity　for　bacterial　inactivation　are　needed　to　address　the　problems　caused　by　outbreak　of　harmful　microorganisms.　In　this　study,　cadmium　indium　sulfide　(CdIn2S4)　microsphere,　which　can　be　synthesized　continuously　by　a　facile　ultrasonic　spray　pyrolysis　method,　was　used　as　an　efficient　photocatalyst　in　inactivation　of　Escherichia　coli　K-12　under　visible　light　(VL)　irradiation　for　the　first　time.　The　as-prepared　CdIn2S4　showed　a　micro-spherical　morphology　with　diameter　of　0.5-1.0μm.　It　had　an　energy　band　gap　of　2.02eV　and　BET　surface　area　of　34.8m2/g.　It　was　found　that　bacterial　cells　could　also　be　effectively　inactivated　inside　a　partition　system　without　the　direct　contact　with　the　photocatalyst,　which　was　attributed　to　the　diffusible　photon-generated　hydrogen　peroxide　(H2O2)　rather　than　hydroxyl　radicals　(OH).　Large　amounts　of　H2O2　were　produced　from　both　conduction　and　valance　bands　with　the　involvement　of　superoxide　(O2-).　The　used　CdIn2S4　could　be　easily　recycled　by　the　partition　system　without　loss　of　activity.　The　destruction　process　of　bacterial　cells　was　from　the　cell　wall　to　the　intracellular　components　as　confirmed　by　TEM　study.　In　addition,　the　O2-　and　OH　radicals　were　also　detected　in　the　CdIn2S4-VL　system　by　ESR　spin-trap　with　DMPO　trapping　technology.　©　2012　Elsevier　B.V.