In　this　paper,　nine　webless　reinforced　concrete　(　RC)　beams　strengthened　by　oblique　CFRP　sheets　(adhesion　angle　of　45°,　CFRP　ratio　of　0.　0835%　)　with　shear-span　ratios　(λ　was　1.　0,1.　5,2.　0)　and　cross-section　sizes　(beam　heights　of　300,　600,　900　mm)　as　the　main　study　variables　were　designed　and　tested　to　investigate　their　shear　performance.　We　concentrated　on　the　examination　of　the　variation　rules　of　damage　mode,　crack　extension　behaviour,　CFRP　fabric　strain,　peak　load,　and　mid-span　deflection　with　the　shear-span　ratio　and　cross-section　size　based　on　the　four-point　bending　loading　test.　The　findings　indicate　that:　the　final　damage　mode　of　the　beam　is　shear　damage　within　the　test　shear-span　ratio　range;with　the　shear-span　ratio　increases　from　1.　0　to　2.　0,　the　load　carrying　capacity　of　the　beam　decreases　from　45%　to　51%　,　the　contribution　of　CFRP　fabric　to　the　shear　load　carrying　capacity　accounts　for　an　increase　of　23%　to　28%　,　and　the　nominal　shear　strength　of　the　beam＇s　cross-section　decreases　from　46%　to　51%　;　the　shear-span　ratio　has　a　relatively　small　effect　on　the　trend　of　the　beam＇s　cross-section　shear　strength　as　it　decreases.　The　size　effect　law　for　webless　RC　beams　strengthened　by　oblique　CFRP　sheets　was　provided　based　on　the　test　data　presented　in　this　study.　It　can　be　applicable　to　the　investigation　of　how　the　shear-span　ratio　affects　the　shear　performance　of　RC　beams　strengthened　by　CFRP　sheets.　©　2024　Science　Press.　All　rights　reserved.