With　the　advantages　of　high　strength,　light　weight,　high　corrosion　and　fatigue　resistance,　and　low　relaxation,　carbon-fiber-reinforced　polymer　(CFRP)　is　an　excellent　cable　material　for　cable-stayed　bridges.　However,　the　relatively　high　unit　price　of　CFRP　compared　to　that　of　steel　may　hinder　the　large-scale　application　of　CFRP　stay　cables.　This　paper　presents　the　economic　comparison　between　long-span　cable-stayed　bridges　using　CFRP　cables　and　the　corresponding　steel　cable-stayed　bridges　through　life-cycle　cost　analysis　(LCCA).　Three　CFRP　cable-stayed　bridges　with　a　main　span　of　600　m,　1200　m,　and　1800　m,　respectively,　along　with　their　steel　counterparts,　were　designed,　and　their　life-cycle　costs　(LCCs)　were　calculated.　The　comparison　of　LCCs　was　not　only　between　the　CFRP　and　steel　cable-stayed　bridges　with　the　same　span,　but　also　between　the　cable-stayed　bridges　with　different　spans.　Furthermore,　the　different　unit　prices　of　CFRP　cables　and　different　replacement　frequencies　of　steel　cables　were　also　investigated.　The　results　show　that　the　initial　design　and　construction　cost　of　the　long-span　CFRP　cable-stayed　bridge　is　higher　than　that　of　the　corresponding　steel　cable-stayed　bridge,　although　using　CFRP　cables　can　reduce　the　materials　used,　primarily　due　to　the　higher　unit　price　of　the　CFRP　cable.　Despite　the　higher　initial　cost,　the　long-span　CFRP　cable-stayed　bridge　can　still　achieve　lower　LCC　than　the　steel　cable-stayed　bridge,　because　it　has　significantly　lower　rehabilitation　cost　and　user　cost,　as　well　as　slightly　lower　vulnerability　cost.　Furthermore,　with　the　increase　in　the　main　span　and　the　decrease　in　the　unit　price　of　CFRP　cables,　the　LCC　advantage　of　the　long-span　CFRP　cable-stayed　bridge　becomes　more　obvious.