Based　on　the　verified　effectiveness　of　the　finite　element　method　used　here,　the　dynamic　responses　of　two　different　hollow　cylinders　with　equal　masses　were　studied　using　LS-DYNA　under　three　different　blast　loadings.　One　of　the　two　cylinders　had　a　sandwich　wall　with　A3　steel　face-sheets　and　close-celled　aluminum　foam　core,　and　the　other　had　a　monolithic　A3　steel　wall.　In　addition,　the　blast-resistance　behaviors　of　five　different　sandwich-walled　hollow　cylinders　were　studied.　The　results　demonstrated　that　the　sandwich-walled　hollow　cylinder　is　superior　to　the　one　with　monolithic　solid　wall　under　the　same　blast　loading,　either　in　deformation　or　in　energy　absorption;　for　the　sandwich-walled　hollow　cylinder,　the　thickness　of　its　inner　face-sheet　should　not　be　bigger　than　that　of　its　outer　face-sheet;　and　only　in　this　condition,　the　global　deformation　of　the　sandwich-walled　hollow　cylinder　can　not　only　be　reduced,　but　also　the　advantage　of　the　energy　absorption　of　foam　core　can　be　taken.