The　paper　deals　with　an　experimental　investigation　and　numerical　simulation　of　moderate　high-strength　reinforced　concrete　(RC)　columns　subjected　to　a　small-eccentric　compressive　loading　(e(0)=0.25h(0)).　A　series　of　tests　on　the　behavior　of　12　geometrically　similar　moderate　high-strength　reinforced　concrete　columns　with　two　different　stirrups　ratios　(i.e.,　0%　and　0.66%)　were　conducted.　The　maximum　structural　size　of　the　square　reinforced　concrete　columns　was　800mm.　A　2D　mesoscale　method　for　the　simulation　of　the　behavior　of　reinforced　concrete　columns　was　established.　The　numerical　tests　on　the　reinforced　concrete　columns　with　larger　stirrup　ratios　(1.2%　and　2.4%)　were　carried　out　complementarily,　based　on　the　fact　that　the　simulation　results　were　consistent　with　the　available　test　observations.　The　failure　patterns,　the　nominal　compressive　stress-strain　relationships,　the　nominal　compressive　strength,　and　the　post-peak　softening　behavior　of　the　reinforced　concrete　columns　were　studied.　Furthermore,　the　influence　of　stirrups　on　failure　behavior　and　size　effect　of　the　reinforced　concrete　columns　was　revealed.　One　can　conclude　that　(1)　the　size　effect　exists　in　the　nominal　compressive　strength　of　the　eccentrically　loaded　high-strength　reinforced　concrete　columns　with　the　four　different　stirrup　ratios;　(2)　comparison　of　the　present　test　results　and　the　size　effect　law　proposed　by　Baant　shows　good　agreement;　(3)　the　presence　of　stirrups　improves　the　nominal　strengths,　makes　the　failure　of　columns　less　brittle,　and　weakens　the　size　effect;　and　(4)　the　proposed　mesoscale　numerical　method　is　capable　of　describing　the　mechanical　behavior　of　eccentrically　loaded　reinforced　concrete　columns.