Laser shock processing (LSP) was employed to treat TC4 titanium alloy Tungsten Inert Gas (TIG) welding joints. HV hardness, tensile property and fatigue life of the TC4 titanium alloy TIG welding joints and the untreated joints were studied. Compared with those joints keeping primal TIG weld bead, microhardness of LSP treatment welding bead zone surface is reduced; however, that of welding heat affected zone surface is are increased. Tensile strength, yield strength, specific elongation, and fatigue life of LSP treatment joints are improved to different extent.