Abstract: Cu₄₆Zr₄₆A_l8 BMGs have been joined by the electron beam welding (EBW) technique. The microstructural transformation, microhardness profile across the welded joint and the tensile property have been analyzed in this paper. The results showed that major microstructure in fusion zone remained amorphous state. Crystallization occurred in the supercooling liquid zone (SLZ) and a large amount of Cu-Zr intermetallics were produced. The microhardness in fusion zone was similar to the base metal and microhardness of supercooling liquid zone was significantly reduced. The tensile strength and toughness of the welded joint were lower than those of base metal. Fracture occurred in the brittle compounds layer of supercooling liquid zone with a typical brittle intergranular fracture mode.