Highly　ordered　metal　Sn　nanodoi　arrays　were　prepared　by　vacuum　electron　beam　evaporation　using　porous　anodic　alumina　(PAA)　membrane　as　the　substrate.　They　were　characterized　by　means　of　scanning　electron　microscopy　(SEM)　and　X-ray　diffraction　(XRD).　SEM　images　indicated　that　the　Sn　nanodot　arrays　are　highly　ordered　and　coincid　with　the　contours　of　porous　anodic　alumina.　The　shape　of　Sn　nanodot　is　spherical　and　the　diameter　approximates　the　pore　diameter　of　the　PAA　membrane.　XRD　showed　that　crystallographic　structures　of　Sn　nanodot　arrays　are　the　same　as　the　bulk　Sri.　The　forming　process　and　mechanism　of　the　Sn　nanodot　array　was　discussed.