Chloride　ingress　governs　the　rebar　corrosion,　significantly　influencing　the　fatigue　life　of　the　RC　structures.　The　S-N　curve　considering　the　chloride　ingress　is　proposed　based　on　the　fatigue　tests　of　nineteen　beams.　The　mesoscale　numerical　method　is　applied　to　simulate　the　chloride　ingress　in　fatigue-loaded　concrete.　The　S-N　curve　combined　with　the　mesoscale　simulation　of　chloride　ingress　is　proved　to　be　reasonable　for　the　fatigue　life　estimating.　Additionally,　it　is　found　that　water-to-cement　ratio　of　＜=　0.4　and　aggregate　content　of　＞=　50%　are　suggested　to　improve　the　fatigue　life,　and　stress　level　is　better　to　consider　for　the　durability　design.