This　paper　presents　the　results　of　nine　concrete　columns　reinforced　with　longitudinal　and　transverse　glass　fiber-reinforced　polymer　(GFRP)　bars　and　two　concrete　columns　reinforced　with　longitudinal　steel　bars　and　transverse　GFRP　bars.　These　specimens　were　tested　under　lateral　cyclic　quasi-static　loading　while　simultaneously　subjected　to　constant　axial　load.　The　influence　of　the　volumetric　ratio　of　stirrups,　the　shear　span　ratio　and　the　axial　load　level　on　the　behavior　of　GFRP-reinforced　concrete　columns　are　discussed.　The　results　showed　that　GFRP-reinforced　concrete　columns　can　have　sufficient　bearing　capacity　and　achieve　high　levels　of　deformability.　The　lateral　drift　ratios　of　all　the　columns　reached　4.08-5.06%,　which　meet　seismic　drift　limitations　in　most　building　codes.　The　evaluation　methodology　of　ductility　coefficient　may　not　assess　the　seismic　deformability　and　resistance　of　GFRP-reinforced　concrete　columns　objectively,　while　the　integrated　performance　index　can　reflect　the　influence　of　the　volumetric　ratio　of　stirrups,　the　shear　span　ratio　and　the　axial　load　on　seismic　performance　comprehensively.　The　results　further　indicate　that　concrete　columns　reinforced　with　GFRP　bars　can　be　successfully　designed　and　used　in　seismic　engineering　if　confined　well.