The　shear　failure　behavior　and　the　size　effect　of　shear　strength　of　carbon　fiber-reinforced　plastic　(CFRP)-reinforced　concrete　beam-column　joints　are　investigated　in　this　study.　The　finite　element　model　for　failure　analysis　of　CFRP-reinforced　concrete　beam-column　joints　was　established　using　a　mesoscale　numerical　method.　The　mesoscale　failure　mode　and　failure　mechanism　of　geometrically　similar　CFRP-reinforced　concrete　beam-column　joints　were　studied,　and　the　influence　of　CFRP-bar　ratio　on　shear　strength　and　size　effect　law　of　joints　was　discussed.　The　simulation　results　show　that　the　nominal　shear　strength　of　CFRP-reinforced　concrete　beam-column　joints　has　an　obvious　size　effect,　and　the　size　effect　of　shear　strength　can　be　alleviated　by　increasing　the　CFRP-bar　ratio.　In　addition,　it　is　found　that　the　size　effect　of　the　nominal　shear　strength　of　concrete　beam-column　joints　with　CFRP　bars　is　more　obvious　than　that　of　reinforced　concrete　(RC)　beam-column　joints.　Based　on　the　size　effect　law　of　nominal　shear　strength　for　RC　beam-column　joints,　considering　the　effect　of　stirrup　ratio　proposed　in　the　previous　work,　along　with　the　numerical　test　results　in　this　study,　the　size　effect　law　was　extended　and　established　for　the　analysis　of　nominal　shear　strength　of　concrete　beam-column　joints　with　CFRP　bars.　©　2022　Chinese　Academy　of　Sciences.　All　rights　reserved.