A typical repair method for fatigue cracks in steel bridge members is the splice plate method. The crack tip is drilled out, and splice plates are added over the crack. For evaluating the remaining fatigue life of the repaired members, it is needed to know the stress of the drilled hole after adding splice plates. In this study, the effect of the splice plateís geometric parameters on the stress reduction of a drilled hole was investigated by tensile tests and parametric FE analyses. As a result, a new method to estimate the stress of the drilled hole was proposed, considering stress carrying mechanism of the splice plate. This method could estimate the stress within 10% error.