Three-dimensional　(3D)　Z-scheme　WO3@HCNS　hollow　nanohybrids　with　intimate　interfacial　contacts　are　constructed　by　assembling　porous　WO3　shells　on　the　outer　surface　of　hollow　carbon　nitride　spheres　(HCNS).　The　structure,　morphology,　optical/electric　and　electrocatalytic　properties　of　the　WO3@HCNS　heterostructures　are　systematically　studied,　and　their　photocatalytic　performance　is　evaluated　by　water　oxidation　to　generate　oxygen　under　visible　light　(lambda　＞　420　nm).　The　optimal　WO3@HCNS　composite　exhibits　a　high　oxygen　evolution　rate　(OER)　of　23　mu　mol.h(-1),　which　is　about　20-fold　that　of　pristine　HCNS　(OER　=　1.2　mu　mol.h(-1)).　The　superior　performance　of　WO3@HCNS　is　mainly　attributed　to　the　unique　Z-scheme　hollow　heterostructures　with　strongly　coupled　interfaces,　which　powerfully　promotes　the　separation　and　migration　of　charge　carriers,　and　the　shuttling　of　mass　transportation.　The　work　may　inspire　future　works　on　fabrication　of　nanoscale　hollow　carbon　nitride-based　Z-schematic　heterostructures　with　tailored　shells　and　tight　junctions　as　high-efficiency　platforms　for　photocatalytic　H2O　splitting.