Abstract: In this paper low carbon steel surfacing layers were formed on 304 stainless steel by electron beam welding with filler wire process to explain the relations between weld appearance and main process parameters. The effects of such welding parameters as electron beam,welding speed,wire feed rate, wire feeding angle and wire feed position on weld appearance were researched. The results showed that the match of weld heat input with wire feed rate was the main factor which determined weld appearance. In the same process,the width of the weld increased while the electron beam increased. Meanwhile, the depth of the weld increased with increasing of the wire feeding angle. In addition,the welding process could be more stable and precise when the front wire feed position was adopted.