Glass　fiber　reinforced　polymer　(GFRP)　composite　bars　have　excellent　durability　compared　to　traditional　steel　reinforcements　but　their　strength　contribution　in　the　design　of　compression　members　is　generally　neglected.　The　non-homogeneous　and　anisotropic　nature　of　GFRP　bars　including　their　complex　behavior　in　compression　and　the　lack　of　standard　testing　procedure　have　hindered　their　use　as　compressive　reinforcements.　To　improve　their　behavior　and　strength　in　compression,　a　novel　technique　has　been　developed　by　winding　additional　GFRP　layers　around　the　longitudinal　fibers.　One,　two　and　three　winding　layers　with　a　thickness　of　1.5　mm　for　each　layer　and　a　winding　angle　of　+/-　83.3　degrees　have　been　used.　Compressive　strength　tests　have　then　been　conducted　on　20　mm　and　30　mm　high　GFRP　bars　with　a　core　diameter　of　20　mm　to　determine　the　improvement　in　compressive　strength,　ductility,　and　failure　behavior.　Test　results　showed　that　the　20　mm　core　diameter　GFRP　bars　have　shown　promising　improvement　in　the　compressive　strength　and　ductility　with　the　increased　number　of　winding　layers　wherein　the　compressive　strength　of　the　20　mm　and　30　mm　high　bars　increased　by　74%　and　63%,　respectively　for　bars　with　three　winding　layers.　Comparison　of　the　mechanical　properties　in　compression　and　tension　showed　that　the　optimum　strength　and　ductility　improvement　can　be　achieved　with　two　winding　layers.　A　simple　theoretical　strength　model　has　been　developed　which　can　reliably　predict　the　compressive　strength　of　the　winded　GFRP　bars.