The　effect　of　FRP　and　reinforcement　corrosion　on　the　restoring　characteristic　of　RC　columns　is　a　key　issue　in　the　seismic　performance　of　existing　RC　structures.　According　to　the　experimental　results,　methods　to　determine　the　restoring　force　and　skeleton　curve　of　RC　corroded　columns　strengthened　with　hybrid　FRP　were　presented　in　this　paper　based　on　the　cross-section　analysis　of　undamaged　RC　element　and　Clough　hysteresis　rule.　Results　show　that　the　skeleton　curve　calculated　using　the　linear　plane　assumption　with　modification　by　bar-slip　model　can　still　be　used　as　the　skeleton　curve　of　RC　corroded　columns　strengthened　with　hybrid　FRP,　and　good　agreement　between　the　calculated　curve　and　the　test　result　was　obtained.　The　restoring　force　model　for　RC　corroded　columns　strengthened　with　hybrid　FRP　can　be　established　using　Clough　hysteresis　rule　with　a　modification　for　unloading　stiffness.　The　basic　theory　for　seismic　damage　rehabilitation　and　evaluation　of　existing　RC　structures　were　presented　finally.