The　experiments　on　the　geometric　bending　stiffness　of　36galfan　cables　and　stainless　steel　cables　were　carried　out　by　frequency　method.　The　natural　vibration　frequencies　of　three　different　diameters　galfan　cables　and　stainless　steel　cables　under　the　three　different　prestress　levels　were　measured.　Then　based　on　Bernoulli-Euler　theory,　an　iterative　solution　method　of　geometric　bending　stiffness　was　proposed.　The　geometric　bending　stiffness　of　three　different　diameters　galfan　cables　and　stainless　steel　cables　were　identified　and　calculated.　The　results　show　that　the　ratio　of　the　geometric　bending　stiffness　to　the　total　section　bending　stiffness　decrease　as　the　diameter　of　the　cable　increases.　The　function　relationship　between　the　ratio　and　diameter　is　obtained.　©　2020,　Editorial　Department　of　Journal　of　Building　Materials.　All　right　reserved.