High-performance　ferromagnetic　materials　are　essential　for　energy　conversion　and　electronic　devices.　However,　the　random　and　nonuniform　magnetization　reversal　in　ferromagnetics　limits　their　performance　that　can　be　achieved.　Here,　through　both　micromagnetism　simulations　and　experiments,　a　directional　magnetization　reversal　that　initiates　first　from　large　grains　toward　smaller　ones　is　discovered　by　engineering　Nd2Fe14B/alpha-Fe　gradient　nanostructures.　Such　directional　magnetization　reversal　enables　a　rare　combination　of　high　magnetization　and　large　coercivity,　thus　leading　to　a　record-high　energy　density　(26　MG　Oe)　for　isotropic　permanent　magnetic　materials,　which　is　approximate　to　50%　higher　than　that　of　its　gradient-free　counterpart.　The　unusual　magnetization　reversal　originates　from　an　ordered　arrangement　of　grain　sizes　in　the　gradient　material,　where　the　large　grains　have　a　lower　reversal　field　than　that　of　the　smaller　ones.　These　findings　open　up　new　opportunities　for　developing　high-performance　magnetic　materials.