Two　linearized　methods　for　the　ultrasonic　inversion　are　formulated　for　the　shape　reconstruction　of　defects　in　an　elastic　material.　The　methods　are　based　on　the　elastodynamic　inverse　Born　and　Kirchhoff　approximations.　From　the　numerical　analysis　for　two　kinds　of　defects,　it　is　verified　that　the　Born　inversion　works　well　for　volumetric　defects　and　the　Kirchhoff　inversion　for　surface　delects.　Combination　of　two　inversion　methods　leads　to　the　separation　of　surface　in　a　part　from　the　volumetric　part　of　the　defect.