Technology of Friction Stir Welding (FSW) as a technique for joining metal is relatively new. In some cases on Aluminum joining, FSW gives better results compared with the Arc Welding processes, including the quality of welds and less distortion. FSW can even use milling machine or drilling machine, by replacing the tools and the appropriate accessories. The purpose of this study is to analyze the effect of process parameters on micro Friction Stir Lap Welding to the tensile load of welds. In this case, Aluminum material A1100, with thickness of 0.4 mm was used. Tool material of HSS material was shaped with micro grinding process. Tool shoulder diameter was 3 mm, while the diameter pin was 2 mm and a length of pin was 0.7 mm. The parameter variations used in this study were the variable of spindle speed (2300, 2600, and 2900 rpm), variable of tool tilt angle (0, 1, 2 degree) and a variable of Feed rate (50, 60, 70 mm/min). Where the variation of these parameters will affect to the mechanical properties of welds (as response) was the tensile load. Analysis and optimization parameters between the micro FSLW parameters with the tensile load of welds, is used a Response Surface Methods (RSM). From the result of experiment and analysis, it is shown that the important welding parameter in Micro Friction Stir Lap welding process is tilt angle.