Disinfection　with　photocatalysis,　compared　to　with　the　conventional　cleanout,　is　both　high　efficient　and　non　contaminative,　but　the　simple　TiO2　photocatalyst　is　showing　to　be　of　low　activity　and　low　active　stability　so　to　be　hardly　practical　application.　In　the　paper,　SO42-/TiO2　were　papered　by　surface　modification　of　TiO2　with　dilute　H2SO4,　and　the　photocatalytic　degradation　of　2-chloroethyl　ethyl　sulfide　(2-CEES)　on　the　samples　was　examined　in　a　fixed-bed　microreactor.　The　examination　show　that　the　acidic　modification　enhanced　both　the　activity　and　the　active　stability　of　TiO2,　and　the　sample　ST200　prepared　by　calcination　at　200°C　was　better　than　ST400　by　calcination　at　400°C.　The　effect　of　water　vapor　content　and　reaction　temperature　on　the　photocatalytic　degradation　of　2-CEES　was　also　tested,　showing　that　the　sample　ST200　had　high　activity　and　stability　at　90°C,　and　kept　a　constant　activity　when　adding　30.5　mL/L　water　vapor　into　the　reactive　system　in　which　2-CEES　initial　concentration　was　low　to　less　than　or　equal　61　μL·L-1.　In　addition,　it　was　found　that　supporting　SO42-/TiO2　on　γ-Al2O3,　SiO2　and　active　carbon　could　improve　on　the　activity　and　stability　of　SO42-/TiO2,　and　on　supports　SiO2　is　the　best　one.