The aim of this study was to determine the distortion tendencies, by means of distortion forces, caused by welding process in welded structures. For this purpose, a rigid lattice frame and force measuring plates (FMPs), which can perceive the distortion forces in the welded structures, were fabricated. Strain-gauge applications with full Wheatstone bridge on the FMPs were carried out. Fabricated FMPs were able to perceive axial tensile and compressive forces in accuracy of 0.36 N. A tackle welded lattice beam was suspended in the rigid frame. FMPs were connected between the rigid frame and the lattice beam for measuring distortion forces. Distortions in the lattice beam, which occurred at the welding of connection points, were perceived as forces by means of FMPs. Distortion forces measured by data logger were transferred to PC by ALMEMO Win Control programme and then distortion analysis was carried out. Distortion effect created during welding and cooling, were determined by using this system.