Abstract-This paper investigates the capability of linear thermoelastic and thermoelastic plastic numerical analysis methods to estimate the welding deformations that occurred due to GMAW process which nowadays becomes an important manufacturing process in modern industries. As already known, distortion is considered as the major stumbling block that can affect the dimensional accuracy and thus able to increase the production costs. Due to this problem, welding distortion is necessarily to be estimated to minimize the negative effects, improve the quality of welded parts and ifnally to reduce production cost. In this study, the elding deformations are simulated by using SYSWELD software and relatively novel FEM software WELD PLANNER developed by ESI Group. Both FEA software are employed to predict welding distortion of double sided T-joint with thickness of 4 mm. The material used for the simulation is low carbon steel. For verification purpose, a series of experiments were performed to measure the weld induced distortion.