A　monotonic　axial　compression　test　was　performed　on　two　series　of　short　column　specimens　in　order　to　investigate　the　size　effect　of　axial　compressive　mechanical　properties　of　confined　concrete.　The　main　test　variables　were　volumetric　ratio　of　stirrup　and　specimen　size.　The　diameter　of　largest　specimen　was　576　mm.　The　test　result　shows　that　as　the　specimen　size　increases,　the　peak　stress　and　the　peak　strain　of　confined　concrete　decreases.　The　relationship　between　ductility　and　specimen　size　is　indistinct.　When　factorial　analysis　method　is　used　to　analyze　the　test　results,　it　can　be　found　that　the　volumetric　ratio　of　stirrup　has　significant　influence　on　peak　stress,　peak　strain　and　ductility　of　confined　concrete.　The　specimen　geometric　size　affects　peak　stress　and　peak　strain　significantly,　but　no　great　influence　on　ductility.　The　interaction　of　volumetric　ratio　and　geometric　size　does　not　affect　peak　stress,　peak　strain　and　ductility　too　much.　Based　on　the　test　and　the　analysis　results,　a　stress-strain　constitutive　model　in　terms　of　column　confined　by　hoops　is　established.　Its　prediction　value　fits　well　with　the　test　result　of　this　thesis.　©,　2015,　Science　Press.　All　right　reserved.