Abstract: Dissimilar material friction welding process between TiAl alloy and GH3039 was studied. Based on the tensile properties of the joint, the welding parameters were optimized preliminarily. The microstructure and mechanism of the welded joint and the composition change of the weld zone were analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results indicate that the friction welding of dissimilar material between TiAl alloy and GH3039 is feasible, under the action of thermo-mechanical coupling in friction welding process, the plastic deformation of thermo-mechanical affected zone on the side of GH3039 is larger than that of TiAl alloy; The alloy elements on both sides of the friction welding interface between TiAl alloy and GH3039 have diffused, a complex organizational structure of the layered intermetallic compounds has been formed. The fracture of welded joint broken in TiAl alloy base metal belongs to typical brittle fracture.