Corrosion and tensile properties of zircaloy-4 cladding tube having a laser welding part in elevated temperature are studied to present the criterion of quality evaluation in nuclear reactor and find the scientific basis of SCC, with laser welding method using by coupling up cladding tube to end cap. In the result of tensile test($400^{circ}C$), the fracture is not happened in the welding part but base metal and the result of corrosion test($400^{circ}C$ 1500psi steam), corrosion rate of the molten zone and PMZ is a little higher than the other zone.