The　macroscopic　mechanical　properties　of　reinforced　concrete　members　are　determined　by　the　mechanical　properties　of　steel　rebar　and　concrete.　In　light　of　the　mesoscopic　heterogeneity,　concrete　is　regarded　as　a　triphase　composite　material　consisting　of　aggregate,　mortar　matrix　and　the　interfacial　transition　zone　(ITZ)　at　meso-scale.　It　is　assumed　that　the　steel　rebar　and　concrete　are　well　bonded.　A　meso-scale　numerical　model　of　reinforced　concrete　columns　subjected　to　eccentric　compressive　loading　is　established.　Several　uniaxial　compressive　tests　of　square　and　rectangular　concrete　specimens　are　conducted.　The　mechanical　parameters　of　the　ITZs　are　fixed　by　an　inversion　method.　The　macroscopic　mechanical　properties　of　reinforced　concrete　column　subjected　to　eccentric　compressive　loading　are　simulated.　The　simulation　results　indicate　that　the　material　heterogeneities　can　be　revealed　sufficiently　by　the　established　meso-scale　numerical　model　compared　with　those　obtained　from　the　macro-scale　model,　and　the　macroscopic　mechanical　properties　of　the　test　specimen　can　be　well　simulated.　The　failure　process　of　the　specimens　can　be　described　elaborately.　Moreover,　the　simulation　results　are　consistent　with　the　experimental　observations.　The　meso-scale　simulation　method　established　in　this　study　provides　a　theoretical　support　to　the　investigation　of　the　size　effect　of　reinforced　concrete　members.　©　2016,　Engineering　Mechanics　Press.　All　right　reserved.