Because welding residual stress is formidable result in electric resistance spot welding process, and it detrimentally affect to fatigue crack initiation and growth at nugget edge of spot welded la p joints, it should be considered in fatigue analysis. Thus, accurate prediction of residual stress is very important. In this study, nonlinear finite element analysis on welding residual stress generated in process of the spot welding was conducted, and their results were compared with experimental data measured by X-ray diffraction method. By using their results, the maximum principal stress considered welding residual stress at nugget edge of the spot welded lap joint subjected to tension-shear load was calculated by superposition method. And, the $Delta$P- $N_f$ relations obtained through fatigue, tests on the IB-type spot welded lap joints was systematically rearranged with the maximum principal stress considered welding residual stress. From the results, it was found th2at fatigue strength of the IB-type spot welded lap joints could be systematically and more reasonably rearranged by the maximum principal stress($sigma$1max-res considered welding residual stress at nugget edge of the spot welding point.