Abstract: To study the remaining fatigue strength and remaining fatigue life of existing stay cable wires with corrosion and fatigue damage, fatigue tests were conducted for steel stay cable wires under three different damage levels and no damage with similar tensile strength. Based on the fatigue fracture morphology characteristics, obtained are the characteristic parameters of corrosion pits as a fatigue crack initiation. Calculated are the stress intensity factors of corrosion pits, and investigated are the fatigue and fracture mechanisms of steel wires. The fatigue stress-life curves of steel wires with different survival probability are fitted using the least-squares method, and calculated are the reduction in remaining fatigue strength and life of stay cable steel wires . Revealed are the effects of damage degree caused by corrosion and fatigue, and the stress ratio on the remaining fatigue strength and life of steel wires . Test results show that fatigue cracks of steel wires without damage derive from the scratch on surface or slag inclusion. The fatigue cracks of existing stay cable steel wires mostly sprout at the corrosion pits with the depth more than 60 µm and the area more than 10000 µm². The crack initiations at the corrosion pits are depended on the fatigue crack propagation threshold. The fatigue fracture of steel wires with existing corrosion and fatigue damage shows both ductile and brittle characteristics. The brittle characteristics of the fatigue fracture become more obvious for steel wires under more severe degree of the existing corrosion and fatigue damage. With the degree of existing corrosion and fatigue damage increases, the slope of the fatigue stress-life curves gradually increases, the remaining fatigue strength decreases significantly, and the fatigue limit at the inflection point of curves tends to disappear. The remaining fatigue strength of damaged steel wires decreases significantly with the stress ratio increases. With the damage degree of existing corrosion and fatigue damage increases, the remaining fatigue strength of steel wires decreases under the same stress range, and life reduction rates increase.