PURPOSE: To manufacture the welded structure of the welded T-joint panel which is simple in structure, low in the cost and free of distortion, and to provide a method for welding the curved panel of the welded T-joint having an appropriate curved surface in the longitudinal direction by controlling the deformation during the welding.

CONSTITUTION: In forming a T-joint by executing the continuous fillet arc welding of a metallic sheet 2 and a longitudinal member 1, the preheating is executed with the high energy beam before the continuous fillet arc welding of the top part of the longitudinal member is executed omitting the tack welding. In addition, the rear side of the fillet welded part of the metallic sheet 2 is preheated with the high energy beam before the continuous fillet arc welding. The T-joint panel having the curved surface in the longitudinal direction is obtained by adjusting the timing of and balance between the heat input of the high energy beam to heat the top part of the longitudinal member 1 and the fillet welding.