An　electricity-gas　coupling　system　with　combined-cycle　gas　turbines　(CCGTs)　is　a　major　form　of　integrated　energy　system.　Due　to　their　flexible　operation　characteristic,　CCGTs　are　often　used　to　track　fluctuations　in　load　and　renewable　energy　sources,　providing　reserve　for　the　integrated　energy　system,　so　it　is　necessary　to　conduct　research　on　the　reserve　allocation　of　CCGTs.　A　reserve　allocation　model　of　the　integrated　energy　system　considering　the　operation　mode　of　CCGTs　was　established.　The　proposed　model　solved　the　problem　that　the　traditional　model　cannot　consider　the　operation　mode　of　CCGTs　so　that　the　reserve　allocation　result　is　too　optimistic,　and　realized　accurate　and　effective　allocation　of　reserve　under　reserve　market　conditions.　Initially,　this　paper　established　a　feasibility　check　model　of　CCGTs＇　reserve　based　on　the　minimum　load-shedding　model　for　gas,　to　make　sure　that　when　in　actual　operation,　natural　gas　system　has　sufficient　adequacy　to　meet　requirements　of　reserve.　Numerical　results　show　that　the　proposed　model　considers　the　operation　mode　of　CCGTs,　overcomes　the　problem　that　the　traditional　linear　model　overestimates　the　ramp　ability　of　CCGTs,　which　may　lead　to　the　actual　reserve　shortage,　and　thus　ensures　the　operation　safety　of　the　system.　The　CCGTs＇　feasibility　check　ensures　the　sufficient　gas　supply　of　CCGTs＇　reserve　in　actual　operation,　guaranteeing　the　feasibility　of　CCGTs＇　reserve.　©　2020　Chin.　Soc.　for　Elec.　Eng.