It is well known that there could be many, more or less, mis-aligned members in ship structures. In oder to evaluate ship strength, it is necessary to know the behavior and its strength of such mis-aligned structures. In this report, as the first step of such investigation, mis-aligned I section joints are subjected to tensile load and their static tensile stength as well as fatigue strength are studied, concluding that these mis-aligned joints may be adequately strengthened by increasing the leg length of fillet weld. However, more systematic and detailed experiments are needed to refine to design and the construction of ships by taking into account of the effect of mis-aligned members.