With a technological advance of the industrial product, weld between the different kind metal is demanded. Adove all, demands for welding of the different kind metals, copper and stainless steel, increase. However, forming a welded joint between stainless steel and a copper is difficult because the physical properties of the two metals - such as thermal conductivity and melting point - are different and they do not form an alloy. In this report, laser welding of copper (C1020) plate and stainless steel (SUS304) plate of thickness 1.5mm using a disk YAG laser was examined. The bondable welding conditions were selected, and the structure of welding copper and stainless steel was evaluated by EPMA and X-ray diffraction. As a result, it was found that copper and stainless steel were mixed and were joint by mechanical linking, when laser irradiation position put off in the copper side from 0.1mm to 0.2mm. In addition, it was found that it didn't separate of each component and didn't generate of new alloy in the weld.