The　microstructure,　microhardness,　tensile　property,　and　endurance　property　of　a　new　high　temperature　titanium　alloy　Ti650　were　studied　after　electron　beam　welding　and　heat　treatment　at　1　000　℃/1　h/AC+700　℃/4　h/AC.　The　results　indicated　that　the　microstructure　of　the　base　metal(BM),　heat　affected　zone(HAZ),　and　fusion　zone(FZ)　all　included　α　phases,　small　amount　β　phases,　and　lots　of　fine　recrystallized　α　phases.　The　corresponding　microhardness　of　joints　was　relatively　even　in　the　range　of　440　HV　to　490　HV.　At　room　temperature,　the　tensile　strength　and　elongation　of　joints　and　BM　were　both　higher　than　1　000　MPa　and　7%~10%.　While　at　650　℃,　those　of　BM　were　about　750　MPa　and　up　to　20%,　and　those　of　joints　were　below　700　MPa　and　10%~14%.　The　endurance　ruptures　of　joints　and　BM　were　both　attributed　to　the　aggregation　of　micro　voids,　and　further　extended　under　the　stress　until　ultimate　fracture.　The　difference　between　joints　and　BM　was　that　the　grain　boundaries　of　the　columnar　crystals　of　joints　promoted　the　propagation　of　crack.　That＇s　why　the　joint　of　Ti650　showed　good　endurance　life　compared　with　the　BM　and　the　results　could　be　fitted　to　a　prediction　equation.　©　2018,　Editorial　Board　of　Material　Science　and　Technology.　All　right　reserved.