We　report　the　self-assembly　of　uniform　CdS　nanospheres/graphene　(CdS　NSPs/GR)　hybrid　nanocomposites　via　electrostatic　interaction　of　positively　charged　CdS　nanospheres　(CdS　NSPs)　with　negatively　charged　graphene　oxide　(GO),　followed　by　GO　reduction　via　a　hydrothermal　treatment.　During　this　facile　two-step　wet　chemistry　process,　reduced　graphene　oxide　(RGO,　also　called　GR)　and　the　intimate　interfacial　contact　between　CdS　NSPs　and　the　GR　sheets　are　achieved.　Importantly,　the　CdS　NSPs/GR　nanocomposites　exhibit　a　much　higher　photocatalytic　performance　than　bare　CdS　NSPs　toward　selective　reduction　of　nitro　organics　to　corresponding　amino　organics　under　visible　light　irradiation.　The　superior　photocatalytic　performance　of　the　CdS　NSPs/GR　nanocomposites　can　be　attributed　to　the　intimate　interfacial　contact　between　CdS　NSPs　and　the　GR　sheets,　which　would　maximize　the　excellent　electron　conductivity　and　mobility　of　GR　that　in　turn　markedly　contributes　to　improving　the　fate　and　transfer　of　photogenerated　charge　carriers　from　CdS　NSPs　under　visible　light　irradiation.　Moreover,　the　photocorrosion　of　CdS　and　the　photodegradation　of　GR　can　be　efficiently　inhibited.　The　excellent　reusability　of　the　CdS　NSPs/GR　nanocomposites　can　be　attributed　to　the　synergetic　effect　of　the　introduction　of　GR　into　the　matrix　of　CdS　NSPs　and　the　addition　of　ammonium　formate　as　quencher　for　photogenerated　holes.　It　is　hoped　that　our　current　work　could　promote　us　to　efficiently　harness　such　a　simple　and　efficient　self-assembly　strategy　to　synthesize　GR-based　semiconductor　composites　with　controlled　morphology　and,　more　significantly,　widen　the　application　of　CdS/GR　nanocomposite　photocatalysts　and　offer　new　inroads　into　exploration　and　utilization　of　GR-based　semiconductor　nanocomposites　as　visible　light　photocatalysts　for　selective　organic　transformations.　©　2013　American　Chemical　Society.