This paper present a study on melting low carbon steel for core wire of welding electrode from MIREX sponge iron. Sponge iron, an advanced material of steelmaking, is produced by direct reduction iron process in solid state. The melting process of 3 grades steels are established. They chimicals components and mechanical properties accord to standard. This study prove, that MIREX sponge iron can be used for material to melting high grades steels with low carbon components and low P, S and they mechanical properties are higher compare with usual steel. The produced steels may be applied for core wire of welding electrode.