The authors investigated an influence of load range on fatigue crack initiation and propagation behavior from weld root into deck plate in orthotropic steel deck using model specimens for the connection between deck plate, transverse rib and trough rib. The results suggested that the difference in the behaviors due to load range were not recognized. It was considered that the results could be explained by that tensile residual stress occurred at the weld root from which fatigue crack initiated. In this study, effect of the stress relief annealing on the crack initiation and propagation behavior has been examined experimentally.