Nanocrystalline　ZnTa2O6　photocatalysts　with　different　crystal　structures　were　prepared　via　a　simple　and　facile　sol-gel　method　in　a　temperature　range　of　650-950　°C.　The　absorption　edges　and　particle　sizes　of　the　samples　were　located　at　about　285　nm　(corresponding　a　band　gap　of　4.35　eV)　and　ranged　from　25　to　150　nm,　respectively.　The　photocatalytic　activities　of　the　samples　were　tested　by　the　degradation　of　methyl　orange　under　UV　light　irradiation.　The　results　indicated　that　the　crystal　structure　of　ZnTa　2O6　was　a　main　factor　for　the　different　photocatalytic　activities　of　the　ZnTa2O6　samples.　Moreover,　the　effects　of　crystallinities　and　surface　areas　of　the　obtained　samples　on　the　catalytic　activities　were　also　discussed.　©　2011　Elsevier　B.V.