A　zircon　coating　was　applied　on　the　surface　of　Ti-6A1-4V　alloy　by　plasma　spray　and　its　effect　on　the　high　temperature　tensile　properties　of　the　alloy　as　well　as　the　oxidation　behavior　of　the　alloy　were　studied.　Tensile　tests　were　conducted　at　850C　with　different　strain　rates　of　10-4s　-1,　10-3s-　1,　10-2s-1　and　10-1s-1.　The　results　show　that　the　elongation　of　the　coated　specimens　is　higher　than　that　of　the　uncoated　ones,　while　the　ultimate　tensile　strength　of　the　alloy　is　not　changed.　An　oxide　film　had　formed　on　the　surface　of　uncoated　Ti-6A1-4V　alloy,　however　no　such　oxide　film　was　found　on　the　coated　alloy　at　the　early　of　stage.　The　coating　can　prevent　oxygen　penetration　into　the　substrate　thus　prevent　embrittlement　of　the　subsurface　zone.　The　ductility　could　be　improved　by　means　of　the　zircon　coating.　The　optical　micrographs　of　the　specimens　show　little　change　in　microstructures　of　the　coated　and　uncoated　specimens.　Zircon　coating　has　no　effect　on　the　microstructure　of　the　substrate　alloy.