La2Sn2O7　(LSO)　micro/nanospheres,　synthesized　by　a　hydrothermal　method,　exhibited　photocatalytic　performance　for　CO2　reduction.　The　evolution　rate　of　the　main　reduction　products　(CH4　and　CO)　was　0.20　and　0.10　μmol　h−1,　respectively.　Loading　of　Au　co-catalyst　over　La2Sn2O7　efficiently　enhanced　the　photocatalytic　activity　of　CO2　reduction.　The　highest　photocatalytic　efficiency　was　obtained　over　1　wt%　Au/La2Sn2O7　with　an　apparent　quantum　yield　(AQY)　of　2.54%.　Characterization　techniques　including　SEM,　TEM,　XRD,　XPS,　DRS,　PL,　and　electrochemical　analysis　were　applied　and　the　physicochemical　properties　of　La2Sn2O7　and　Au/La2Sn2O7　samples　are　discussed.　A　possible　mechanism　of　photocatalytic　CO2　reduction　over　Au/La2Sn2O7　is　proposed.　©　The　Royal　Society　of　Chemistry.