In　order　to　research　the　feasibility　of　structural　seismic　retrofit　with　Hybrid　FRP(HFRP),　seven　square　reinforced　concrete　columns　are　tested　under　low　cyclic　alternate　load　to　investigate　the　performances　such　as　seismic　behaviors,　failure　mode,　hysteresis　curves,　skeleton　curves,　ductility,　degradation　of　stiffness　and　energy　consumption　of　square　columns　strengthened　with　HFRP.　The　effects　of　the　axial　load　ratio,　the　amount　of　HFRP　and　the　stirrup　ratio　on　the　seismic　performance　of　square　columns　strengthened　with　HFRP　are　studied.　The　results　show　that　the　seismic　performance　can　be　improved　effectively　for　square　columns　strengthened　with　HFRP.　The　effect　of　axial　load　ratio　is　great,　and　HFRP　can　confine　concrete　more　effectively　when　the　axial　load　ratio　is　low.　The　higher　the　axial　load　ratio　is,　the　lower　the　confinement　and　the　ductility　are.　The　results　also　indicate　that　increasing　the　amount　of　HFRP　can　improve　the　seismic　performance　effectively　when　the　axial　load　ratio　is　low　but　barely　have　any　effect　when　the　axial　load　ratio　is　high.　The　seismic　performance　of　the　square　columns　can　be　improved　significantly　by　increasing　the　stirrup　ratio.