The　effect　of　hole　number　and　the　diameter　of　holes　of　perforated　pipe　on　the　attenuation　of　torsional　guided　wave　mode,　T(0,1),　at　low　frequency　is　investigated　by　finite　element　simulation　and　experiment.　First,　propagation　characteristics　of　torsional　guided　waves　at　low　frequency　in　free　steel　pipe　are　theoretically　analyzed.　Then,　group　velocities　of　T(0,1)　mode　at　different　frequencies　are　obtained　by　finite　element　simulation　and　experiment　and　compared　with　theoretical　dispersion　curve　of　this　mode.　Result　show　that　finite　element　simulation　is　valid,　and　the　excitability　of　T(0,1)　mode　by　thickness　shear　mode　transducers　is　effective.　Based　on　this,　the　fittest　excitation　frequency　for　T(0,1)　mode　inspection　of　perforated　pipe　is　confirmed　to　be　30　kHz.　Finally,　both　finite　element　simulation　and　experimental　results　show　that　the　signal　amplitude　of　T(0,1)　mode　at　30　kHz　decreases　in　different　extents　along　with　the　increase　of　the　hole　number　and　the　diameter　of　the　hole.　These　results　provide　a　foundation　for　nondestructive　inspection　of　perforated　pipes　by　using　T(0,1)　mode　at　low　frequency.　©,　2015,　Beijing　University　of　Technology.　All　right　reserved.