An effective plate bending process by line-heating can be achieved when the heating conditions are properly selected to produce desirable bending or inplane deformations. To make such decisions on the heating condition, the relation between heating conditions and deformations must be clarified. For this purpose, the authors studied the similarity rule holds for the line-heating process and derived two parameters governing the deformation. Also, a new 3-dimensional FEM code is developed as a versatile tool to replace costly experiments. Its validity is examined through a comparison with an experiment and it is applied to study general relations between the parameters and the deformations of plates.