In　this　article,　three　dimensional　Born　inverse　scattering　method　is　modified　to　convenient　form　(Born　inversion　technique)　to　reconstruct　the　shape　of　a　three-dimensional　flaw　in　a　cylindrical　specimen.　In　this　technique,　a　measurement　plane　is　restricted　to　the　plane　perpendicular　to　the　axis　of　the　cylindrical　specimen.　Thus　the　cross-sectional　image　of　the　flaw　can　be　obtained.　By　moving　the　measurement　plane　along　the　axis　of　the　cylindrical　specimen,　the　cross-sectional　image　is　obtained　for　each　measurement　plane.　The　three-dimensional　flaw　image　is　reconstructed　by　piling　up　the　obtained　cross-sectional　images.　Cylindrical　specimen　with　an　eccentric　circular　cylindrical　cavity　model　is　prepared.　The　performance　of　Born　inversion　technique　to　reconstruct　the　three-dimensional　flaw　is　proved　by　using　the　experimentally　measured　waveforms.　At　the　same　time,　the　numerical　results　are　obtained　from　all　directions　by　finite　element　method.　From　the　numerical　analysis　and　experimental　research　for　the　eccentric　circular　cylindrical　defect,　it　can　be　said　that　the　modified　method　is　an　effective　mean　of　shape　reconstruction　and　it　can　reconstruct　an　eccentric　defect　that　has　a　characteristic　size　of　4　mm.　It　is　also　proved　that　Born　inversion　technique　works　well　for　the　volume　type　flaw.　©　2013　Asian　Network　for　Scientific　Information.