Photoelectrochemical　(PEC)　splitting　of　water　to　produce　hydrogen　without　external　bias　is　an　important　approach　to　resolve　the　serious　energy　crisis.　Herein,　we　prepared　a　PEC　cell　system　based　on　the　WO3/Cu2O　heterojunction　in　situ　grown　on　the　FTO　glass　substrates　by　a　seed-mediated　hydrothermal　followed　by　electrodeposition　method.　Under　visible　light　illumination,　the　pure　WO3　exhibited　no　photocurrent　at　0　V　vs.　RHR　in　aqueous　Na2SO4　and　the　pure　Cu2O　struggled　with　serious　photo-corrosion.　By　contrast,　the　obtained　Z-scheme　WO3/Cu2O　0-30　min　heterojunction　can　not　only　effectively　suppress　the　corrosion　of　Cu　2　0　but　also　obtained　a　photocurrent　density　of　12　mu　A　cm(-2)　without　external　bias　or　adding　sacrificial　agent.　Additionally,　the　possible　mechanism　of　a　Z-scheme　system　was　also　proposed　based　on　the　XPS　analysis　and　the　experimental　results.　Thus,　this　study　reveals　that　the　as-obtained　Z-scheme　WO3/Cu2O-30　min　heterojunction　has　a　great　prospect　in　the　PEC　cell　system　without　external　bias.