In general, structural integrity of rolling stock structures should last more than 25 years. During the lifetime corrosive degradation occurs. For structural design and diagnosis, quantitative relationship between corrosive degradation and variation of mechanical properties such as tensile strength and fatigue strength is needed. In this study, electrochemical corrosion tests, atmospheric corrosion tests and fatigue tests of corroded specimens were carried out. The electrochemical characteristics of SS400, SM490A, SUS205L and SUS304 were examined. At regular intervals tensile and fatigue tests were carried out by using specimens of SM490A and SS400 on the atmospheric corrosion test bed. The fatigue strength decreases as the atmospheric corrosion period increases. In addition, the effect of heat treatment on the tensile and fatigue behavior was studied.