The　size　effect　behavior　of　reinforced　concrete　(RC)　components　is　caused　mainly　by　1)　the　heterogeneity　of　concrete　itself,　and　2)　the　complex　mutual　effects　between　concrete　and　steel　rebar.　Considering　of　the　mesoscopic　heterogeneity,　it　is　assumed　that　the　steel　rebar　and　concrete　is　well　bonded.　A　series　of　meso-scale　mechanical　analysis　models　of　RC　columns　subjected　to　axial　compressive　loading　are　set　up.　First,　the　mechanical　parameters　of　the　meso　components　are　confirmed　by　an　inversion　method　based　on　the　simulation　of　compressive　mechanical　properties　test　of　a　concrete　specimen.　Then,　the　damage　process　of　RC　column　subjected　to　axial　compressive　loading　is　simulated　at　macro-and　meso-scale.　The　size　effect　of　the　nominal　compressive　strength　of　RC　components　is　discussed.　The　mesoscopic　simulation　results　of　this　work　follows　closely　the　test　results.　The　rationality　of　the　established　mesoscopic　analysis　method　for　the　research　of　size　effect　of　RC　components　has　been　verified.　©　2016,　China　Water　Power　Press.　All　right　reserved.