The　CdS　nanowires-reduced　graphene　oxide　nanocomposites　(CdS　NWs-RGO　NCs)　combining　one-dimensional　(1-D)　with　two-dimensional　(2-D)　structures　are　successfully　synthesized　by　a　simple　and　efficient　electrostatic　self-assembly　method,　followed　by　a　hydrothermal　reduction　process.　The　probe　reactions　for　photocatalytic　selective　reduction　of　aromatic　nitro　organics　in　water　under　visible　light　irradiation　are　utilized　to　evaluate　the　photoactivity　of　the　as-prepared　CdS　NWs-RGO　NCs.　The　CdS　NWs-RGO　NCs　exhibit　significantly　enhanced　photoactivity　as　compared　with　the　CdS　nanowires　(CdS　NWs).　The　addition　of　RGO　into　the　matrix　of　CdS　NWs　in　a　controlled　manner　is　able　to　efficiently　enhance　the　lifetime　and　transfer　of　photogenerated　charge　carriers　from　CdS　NWs　under　visible　light　irradiation.　Furthermore,　the　presence　of　RGO　also　improves　the　adsorption　capacity　of　CdS　NWs-RGO　NCs　toward　aromatic　nitro　organics.　These　two　primary　factors　result　in　the　drastic　photoactivity　improvement　of　CdS　NWs-RGO　NCs　toward　selective　reduction　of　nitro　organics　to　the　corresponding　amino　organics　in　water　under　visible　light　irradiation.　In　addition,　the　possible　photocatalytic　reaction　mechanism　is　proposed.　It　is　hoped　that　our　work　could　not　only　offer　useful　information　on　the　fabrication　of　various　specific　1-D　semiconductor-2-D　RGO　nanocomposites　but　also　open　a　new　window　of　such　1-D　semiconductor-2-D　RGO　nanocomposites　as　visible　light　photocatalyst　in　the　promising　field　of　selective　organic　transformations.　©　2013　American　Chemical　Society.