To　explore　the　influences　of　plastic　stress　and　residual　stress　on　the　magnetization　of　ferromagnetic　steel　in　geomagnetic　field,　series　of　experiments　and　analyses　are　conducted　in　this　paper.　Two　different　types　of　specimens　made　of　Q195　carbon　steel　with/without　initial　geometric　discontinuities　are　manufactured.　Various　plastic　tensile　stresses　are　introduced　into　the　specimens　and　the　corresponding　applied　stresses,　deformation　distributions　and　residual　magnetic　fields　of　specimens　are　measured.　The　gradients　of　the　residual　magnetic　field　of　the　specimens　are　computed　and　the　relationship　between　the　residual　magnetic　field　and　the　plastic　loading　stress　is　summarized.　It　is　concluded　that　the　intensity　of　magnetization　of　ferromagnetic　steel　in　geomagnetic　field　increases　with　the　plastic　stress,　but　scattered　by　the　dislocation.　The　influences　of　residual　stress　on　the　magnetization　of　ferromagnetic　steel　are　not　significant　in　the　geomagnetic　field.　©　2015　The　authors　and　IOS　Press.　All　rights　reserved.