The　photocatalytic　reduction　of　CO2　into　energy-intensive　hydrocarbon　fuels　is　promising　to　solve　environment　and　energy　issues.　Here,　elemental　sulfur　supported　on　ultrathin　titanic　acid　nanosheets　(S/HTO)　heterostructure　is　designed　and　synthesized　by　loading　different　weight　contents　of　elemental　S　on　HTO　nanosheets　via　a　simple　in-situ　disproportionation-assembly　process.　The　as-designed　S/HTO　heterostructure　not　only　enhances　light　absorption　and　facilitates　CO2　adsorption,　but　also　significantly　promotes　the　interfacial　charge　transport,　and　suppresses　the　recombination　of　photogenerated　charge　carriers.　As　a　consequence,　the　as-prepared　S/HTO　heterostructure　exhibits　enhanced　performance　in　photocatalytic　CO2　reduction　under　simulated　solar　light　illumination.　A　CH4　yield　rate　of　1.92　mu　mol　h-1　g-1　is　obtained　over　the　optimal　15S/HTO　composite　without　the　using　of　cocatalyst　and　sacrificial　agent.　The　photoactivity　is　5.4-fold　and　23-fold　larger　than　that　of　HTO　nanosheets　and　blank　S,　respectively.　In　addition,　the　S/HTO　hybrid　composite　also　presents　high　stability　for　the　production　of　CH4.