Cladding metals have been widely applied to many fields because they have many excellentphysical, chemical and mechanical properties that can not be obtained from the single metals. There are manyconventional processes for manufacturing cladding metals, for example roll bonding, diffusion bonding, explosivewelding, extrusion cladding and casting cladding. Among these processes, continuous casting is an ideal processto prepare cladding metals which has the advantages of high production efficiency, low production cost and goodinterface bonding. This process can make two metals contact directly by the ways of one liquid-one liquid, oneliquid-one solid or one liquid-one semi-solid and then the good metallurgical bonding can be obtained. So, thisprocess is extensively studied by researchers engaging in material processing. The process of the directwater-cooled continuous casting to fabricate cladding 3003/4004 aluminum alloy circular ingot is researched inthis paper. The 3003 aluminum alloy has excellent corrosion resistance, low strength and high melting point, whilethe 4004 aluminum alloy has poor corrosion resistance, high strength and low melting point. The cladding3003/4004 aluminum alloy material can combine the advantages of two metals and can be widely used in manyfields, especially in car engine and air conditioning heat sink. To obtain the good interface bonding, a special innermold with the single-side cooling capability was applied in this process. By the special inner mold, the two alloyscan make the contact of one liquid-one solid or one liquid-onesemi-solid on the interface. The solidification structure and elemental distribution near the interfaceof cladding ingot were systematically detected by OM, SEM and EPAM. Tensile test was carried out to evaluate theinterface bonding strength. The OM results indicated thatthe interface of cladding 3003/4004 aluminum alloy ingot was clear without gas holes and slag inclusion. Mostgrains were equiaxed in the cross-section of cladding 3003/4004 aluminum alloy circular ingot. The EPAM resultssuggested that the interdiffusion of alloy elements in 3003 and 4004 alloy occurred and there was an about 30μmwide diffusion layer near the interface. The entire tensile specimen fractured in the sides of 3003 alloy with theaverage ultimate tensile strength of 107.7 MPa, indicating that the interface bonding strength of cladding ingotwas higher than the ultimate tensile strength of 3003 alloy and the good metallurgical bonding near the interface wasobtained by this process.