Artificial　photosynthesis　is　considered　a　promising　strategy　to　mitigate　environmental　issues　and　energy　crises.　Herein,　one-dimensional　oxide-semiconductor　(TiO2-nanofiber,　TNF)　and　polyarylether-based　covalent　organic　framework　(COF-318)　were　composed　to　form　a　visible-light　responsive　heterojunction　(COF-318/TNF)　for　artificial　photosynthesis　by　simultaneously　triggering　CO2　reduction　and　H2O　oxidation.　Without　additional　sacrificial　agents,　photosensitizers　or　cocatalysts,　the　optimal　sample　COF-318/TNF-15　exhibited　CO2-to-CO　conversion　efficiency　of　70.1　+/-　0.7　mu　mol.g(-　1).h(-1),　12.7　times　higher　than　that　of　COF-318.　The　molar　ratio　of　produced　CO　to　O2　was　about　2:1,　suggesting　H2O　was　the　electron　donor　in　the　photocatalytic　process.　Pho-toelectrochemical　measurements　and　time-resolved　transient　absorption　spectra　illustrated　the　high　separation/　transfer　efficiency　of　photo-generated　charges　in　COF-318/TNF-15,　which　was　attributed　to　the　construction　of　heterojunction　and　the　specific　one-dimensional　property　of　TiO2　nanofibers.　During　the　CO2　photoreduction,　HCOO*　was　detected　as　the　key　intermediate　for　CO　production　according　to　the　in-situ　FT-IR　analysis.　This　work　provides　a　new　route　for　the　rational　design　of　organic-inorganic　heterogeneous　photocatalysts　for　visible-light　-driven　CO2　reduction.