Having undergone accelerative calendar corrosion, a plate with a central hole of LC4CS alloy was subjected to constant amplitude cyclic loads after a tensile overload. From such an experiment, two points could be studied: the interaction between corrosion and overload, and the contribution of this interaction to fatigue life. The analysis of experiment data showed that when overload-ratio was fixed, the logarithm fatigue life of specimen linearly descended with the increase of corrosion degree, and the dispersion increased. For small overload-ratio, the contribution of corrosion and overload to fatigue life approximately canceled out. But for large overload-ratio, overload retardation notably prolonged fatigue life and corrosion before overload seemed to amplify the prolonging.