This article presents a study on effects of some welding parameters on the stress and distortion of pipe joints using Gas Tungsten Arc Welding (GTAW) process. The welded pipe joints are established by Comsol software; while heat generation of GTAW process is also modeled and set up to simulate temperature, stress, and distortion. Results show that welding conditions including welding current, voltage and travel speed influence welding temperature and stress as well as distortion of the pipe welding. The welding stress and distortion increase with an increase in the welding current and voltage. As they increase with a decrease in welding speed. Research results can be a reliable tool to quickly predict the stress and distortion of the weld joint. Besides, from the results, a welding condition can be selected to obtain appropriate welding stress and distortion.