Nanosized　Y2Sn2O7　powder　photocatalysts　with　different　particle　sizes　were　synthesized　through　the　low　temperature　hydrothermal　method　by　using　different　organic　agents.　The　samples　were　characterized　by　X-ray　diffractometer　(XRD),　scanning　electron　microscope　(SEM),　transmission　electron　microscope　(TEM),　surface　area　and　porosity　analyzer,　and　ultraviolet-visible　(UV-vis)　spectroscopes.　Photocatalytic　measurements　showed　Y2Sn2O7　nanocrystals　with　about　10nm　particle　sizes　possess　superior　photocatalytic　properties　in　water　purification　and　may　find　potential　application　in　related　fields.　(c)　2006　Elsevier　B.V.　All　rights　reserved.