Metal-organic　framework　(MOF)　NH2-Uio-66(Zr)　exhibits　pho-tocatalytic　activity　for　CO2　reduction　in　the　presence　of　triethanolamine　as　sacrificial　agent　under　visible-light　irradiation.　Photoinduced　electron　transfer　from　the　excited　2-aminoterephthalate　(ATA)　to　Zr　oxo　clusters　in　NH2-Uio-66(Zr)　was　for　the　first　time　revealed　by　photoluminescence　studies.　Generation　of　ZrIII　and　its　involvement　in　photocatalytic　CO2　reduction　was　confirmed　by　ESR　analysis.　Moreover,　NH2-Uio-66(Zr)　with　mixed　ATA　and　2,　5-diaminoterephthalate　(DTA)　li-gands　was　prepared　and　shown　to　exhibit　higher　performance　for　photocatalytic　CO2　reduction　due　to　its　enhanced　light　adsorption　and　increased　adsorption　of　CO2.　This　study　provides　a　better　understanding　of　photocatalyt-ic　CO2　reduction　over　MOF-based　photocatalysts　and　also　demonstrates　the　great　potential　of　using　MOFs　as　highly　stable,　molecularly　tunable,　and　recyclable　photocatalysts　in　CO2　reduction.　©　2013　Wiley-VCH　Verlag　GmbH　&　Co.　KGaA.