Nitrogen　plays　a　key　role　in　tailoring　the　surface　structures　in　WC–Co–Cubic　graded　cemented　carbides.　In　this　study,　graded　cemented　carbides　were　sintered　at　1450　°C　for　2　h　in　a　N-free　atmosphere　using　TiN,　ZrN,　and　HfN　as　multiple　N　sources.　The　elemental　and　compositional　distributions　of　the　resultant　cemented　carbides　were　measured　to　determine　the　microstructural　evolution　in　the　graded　surface　layer.　For　alloys　incorporated　with　different　N　sources,　two　key　characteristics,　the　residual　cubic　phase　and　thickness　of　the　graded　layer,　were　investigated.　It　was　revealed　that　the　thermodynamic　formation　energies　of　the　cubic　nitrides　was　the　main　factor　to　the　microstructural　evolution.　In　addition,　the　hardness　distributions　in　the　graded　layers　were　measured　using　micro-indentation　tests.　Overall,　a　relationship　between　microstructure　and　hardness　was　established　from　the　surface　to　the　core　of　the　investigated　materials.　©　2022