Abstract: Scanning waveform is one of the welding processes of electron beam welding. But it is unclear if scanning waveform has influence on the weld seam formation. TC4 titanium alloy of 3mm thickness was welded by vacuum electron beam. 11 kinds of scanning welding were used to weld and the influence of scanning waveform on weld shaping was investigated. The results show that scanning waveform has no obvious influence on the weld surface appearance. The cross section appearances of the weld seam with different kinds of scanning waveforms are all wedge shape. The scanning waveform of Triangular wave, rectangular wave and saw-tooth wave in the X-direction, triangle wave in the Y-direction result in single side undercut defects. The effects of the scanning waveforms on the weld width and the penetration are random fluctuation while the ratio of depth to width was invariable.