The welded joint of a dissimilar titanium alloy was obtained via inertial friction welding technology. The characteristics of the bonding interface and the microstructure of the welded joint were investigated via optical microscopy, scanning electron microscopy and electron backscattered diffraction. The results show that fine, equiaxed grains and interdiffusion bands of the elements Mo and Sn were formed in the weld zone under the high temperature and plastic deformation of the inertial friction welding. The weld zone and thermo-mechanically affected zone formed  ⟨1¯21¯0⟩" role="presentation"> ⟨1̲21̲0⟩ ⟨ 1 ¯ 2 1 ¯ 0 ⟩  α texture and  ⟨111⟩" role="presentation"> ⟨111⟩ ⟨ 111 ⟩  β texture, respectively.