Large　Ta2O5　single　crystal　with　high-dielectric　permittivity　was　successfully　grown　by　floating　zone　(FZ)　method　under　air　atmosphere.　The　grown　crystal　that　has　been　obtained　was　typically　about　8　mm　in　diameter　and　90　mm　in　length.　The　crystal　growth　parameters　were　optimized.　The　crystal　symmetry,　characterized　by　means　of　X-ray　diffraction　(XRD),　was　found　to　be　tetragonal.　The　relative　permittivity　and　loss　tangent　along　growth　and　[001]　direction　were　measured　in　the　temperature　range　between　-200　degrees　C　and　200　degrees　C,　which　showed　a　strong　dielectric　anisotropy.　At　a　frequency　of　1　MHz　and　20　degrees　C,　the　dielectric　permittivity　along　the　growth　direction　and　[001]　direction　are　81.17　and　25.04　respectively.　The　stabilization　of　high-temperature　phase　can　explain　the　dielectric　enhancement.