Friction stir welding (FSW) is a process in the solid state in which heat is generated due to friction between welding tool and work piece. FSW has extensive effect on the microstructure, weld quality, and mechanical properties. The purpose of this investigation is to study and to predict the heat generated in Aluminum alloy plates welded by FSW method. A three dimensional model was developed by LS-Dyna software, using finite element method. An appropriate heating cycle has been proposed for aluminum 6061 alloy. The investigated parameters in this study were linear velocity and rotational velocity. Finally, results from numerical and experimental data was compared and verified