The　C-doped　CdO　photocatalysts　were　simply　prepared　by　high-temperature　solid-state　process.　The　as-prepared　photocatalysts　were　characterized　by　X-ray　powder　diffraction　(XRD),　diffuse　reflectance　spectroscopy　(UV-Vis　DRS),　scanning　electron　microscopy　(SEM)　and　X-ray　photoelectron　spectroscopy　(XPS).　The　results　demonstrated　that　the　carbon　was　doped　into　CdO,　resulting　in　the　red-shift　of　the　optical　absorption　of　CdO.　The　photocatalytic　behavior　of　CdO　and　C-doped　CdO　was　evaluated　under　the　visible　light　irradiation　by　using　the　photocatalytic　hydrogen　evolution　as　a　model　reaction.　The　C-doped　CdO　photocatalysts　had　higher　photocatalytic　activity　over　parent　CdO　under　visible　light　irradiation.　The　results　indicated　that　the　H-2　production　was　due　to　the　existence　of　CdS　and　the　enhancement　of　visible　light　photocatalytic　activity　of　H-2　production　was　originated　from　the　doping　of　carbon　into　the　CdO　lattice.　The　probably　reaction　mechanism　was　also　discussed　and　proposed.