The friction stir welding (FSW) is a comparatively innovative solid-state joining process. This joining mechanism is extremely energy efficient, environment friendly and multitalented. The aim of this manuscript is better improvement to the relationship between in the welding parameters and mechanical properties of the aluminum alloy AA6061T-6 type using for the friction stir welding. The effect of the various processing parameters play an important role in the quality of welded joining and the processing parameters are tool rotational speed, traverse speed, axial force and tool geometry play. This paper examine the effect of the tool pin profile and the friction stir welding parameters that on the microstructure and mechanical properties of the aluminum alloy 6061 type for welded join prepared by friction stir welding . It has been establish that prefect grain microstructure is obtained by cylindrical pin profile but they using the square pin profile is a higher strength welded joints are formed. Index Terms-Friction stir welding, 6061 aluminium alloy, tool pin profile, tensile properties.