Nitrogen-doped　and　carbon　species　decorated　TiO2　composites　(Cts/TiO2)　are　prepared　by　using　chitosan　as　a　natural　nitrogen　and　carbon　source　to　combine　with　TiO2　by　a　facile　and　low-cost　method　for　the　first　time.　Their　structures　and　properties　are　characterized　by　X-ray　diffraction　(XRD),　UV-vis　diffuse　reflectance　spectroscopy　(DRS),　Fourier-transform　infrared　spectroscopy　(FT-IR),　X-ray　photoelectron　spectroscopy　(XPS),　N2　adsorption-desorption　isotherms　(BET),　and　electron　spin　resonance　spectroscopy　(ESR).　The　results　show　that　the　visible　light　absorption　range　of　the　composites　even　can　be　extended　to　650nm.　Photocatalytic　degradation　of　Rhodamine　B　(RhB)　under　visible　light　(420nm<λ<　800nm)　irradiation　is　used　as　a　model　reaction　to　evaluate　the　photocatalytic　activity　of　the　composites.　When　the　additive　amount　of　chitosan　is　0.25g,　the　sample　Cts/TiO2-25　possesses　the　highest　activity,　which　is　over　4.8　times　of　N-TiO2.　The　detection　of　active　species　during　the　photocatalytic　process　shows　that　superoxide　radicals　(O2-)　play　the　most　important　role,　then　the　probable　degradation　mechanism　of　the　photocatalysts　is　proposed　simultaneously.　It　is　hoped　that　our　work　will　open　a　new　doorway　to　use　a　simple　and　green　method　to　get　high-efficiency　TiO2-based　photocatalysts.　©　2015　Elsevier　B.V.