Magnetic　Barkhausen　noise　(MBN),　sensitive　to　the　microstructure　of　materials,　can　be　applied　in　the　surface　decarburization　depth　detection　of　ferromagnetic　specimens.　However,　the　effects　of　core　microstructures　on　the　determination　results　of　decarburization　depth　have　not　been　explored.　In　this　study,　MBN　was　employed　to　evaluate　the　magnetic　properties　of　the　decarburized　60Si2Mn　spring　steels　with　martensitic　and　pearlitic　core　microstructures.　Spring　steel　samples　were　austenitized　at　different　times　to　generate　different　decarburization　depths.　Seven　magnetic　features　were　extracted　from　the　MBN　butterfly　profiles.　We　used　the　variation　coefficient,　linear　correlation　coefficient,　and　normalized　sensitivity　to　discuss　the　influence　of　the　core　microstructures　on　these　seven　features.　The　different　core　microstructures　led　to　a　large　difference　in　the　ability　of　MBN　features　to　characterize　the　decarburization　layer　depth.　However,　three　features　of　MBN　butterfly　profiles　demonstrated　an　approximately　linear　dependency　(linear　correlation　coefficient　＞　94%)　on　surface　decarburization　depth　and　monotonically　increased　with　the　increase　in　depth　in　both　core　microstructures　of　spring　steels.