Abstract: The microstructures and properties of Ti17 alloy joints welded by inertia friction welding(IFW) were investigated by room-temperature tensile test, high-temperature tensile test and metallographic analyses.The results show that the joint with good performance at room and high temperature for Ti17 alloy can be obtained in IFW.Both the tensile strengths of welded joints at room temperature and at high temperature are not less than those of the base metal.The microstructure of Ti17 alloy is α+β phase, and the needle β phase is distributing on the α phase.While welding, different welding parameters can not affect the microstructures of the HAZ and the weld seam.The microstructure of HAZ is the same as that of the base metal, and that of the welded seam is fine equiaxed crystal.