Focuses　on　the　seismic　performance　of　carbon　fiber-reinforced　polymer　(CFRP)　reinforced　concrete　members　wherein　the　bonding　characteristics　between　the　CFRP　bars　and　concrete　play　an　essential　role,　this　paper　focuses　on　deriving　simplified　formulas　of　the　bond　stress-slip　relationship　by　a　mesoscopic　numerical　approach.　All　mesoscopic　factors　that　influence　remarkably　the　bond　properties　are　considered.　Influences　of　rebar　diameters,　rib　heights,　rib　width-to-spacing　ratios,　rib　spacings,　embedment　lengths　and　concrete　strengths　on　the　bond　resistance　and　the　residual　bond　stress　are　analyzed.　Based　on　the　numerical　results,　explicit　formula　of　the　bond　stress　on　the　interface　between　the　CFRP　bars　and　the　concrete　is　written　as　a　function　of　the　above-mentioned　mesoscopic　factors.　Interestingly,　it　is　found　that　all　formulas　can　be　rewritten　into　a　uniform　form.　Predictions　of　the　bond　stress　by　the　proposed　formulas　show　good　consistencies　with　experimental　results,　and　the　proposed　formulas　allow　a　full　understanding　of　the　related　debonding　mechanism　for　the　CFRP　bar-concrete　interface　of　CFRP　reinforced　concrete　undergoing　reversed　cyclic　loading.