Abstract: The influences of five different spatial relationships between beam and wire on welding stability and weld appearance were studied during electron beam welding. The results show that the spatial relationships between beam and wire could obviously affect the weld appearance by changing the distribution of welding energy and transfer features of filling wire. The welding process was stable and the weld appearance was good in autogenous welding with separated and partially intersecting relationships between beam and wire. Nevertheless, poor stability and weld appearance could occur by the relationships between beam and wire completely intersecting and non-contacting. The weld depth under different spatial relationships between beam and wire could declined as the following sequence: autogenous, separated, partially intersecting, completely intersecting and non-contacting. Meanwhile, the weld width under non-contacting condition was the smallest among all the different relationships, but those under the other relationships had almost the same value. In addition, the weld reinforcement decreased as sequence of non-contacting, completely intersecting, separated, partially intersecting and autogenous welding.