Spin　engineering　is　recognized　as　a　promising　strategy　that　modulates　the　association　between　d-orbital　electrons　and　the　oxygenated　species,　and　enhances　the　catalytic　kinetics.　However,　few　efforts　have　been　made　to　clarify　whether　spin　engineering　could　make　a　considerable　enhancement　for　electrocatalytic　water　oxidation.　Herein,　we　report　the　spin　engineering　of　a　nanocage-structured　(Co,Ni)Se-2/C@FeOOH,　that　showed　significant　oxygen　evolution　reaction　(OER)　activity.　Magnetization　measurement　presented　that　the　(Co,Ni)Se-2/C@FeOOH　sample　possesses　higher　polarization　spin　number　(mu(b)　=　6.966　mu　B/f.u.)　compared　with　that　of　the　(Co,Ni)Se-2/C　sample　(mu(b)　=　6.398　mu　B/f.u.),　for　which　the　enlarged　spin　polarization　number　favors　the　adsorption　and　desorption　energy　of　the　intermediate　oxygenated　species,　as　confirmed　by　surface　valance　band　spectra.　Consequently,　the　(Co,Ni)Se-2/C@FeOOH　affords　remarkable　OER　product　with　a　low　overpotential　of　241　mV　at　a　current　of　10　mA　cm(-2)　and　small　Tafel　slope　of　44　mV　dec(-1)　in　1.0　mol/L　KOH　alkaline　solution,　significantly　surpassing　the　parent　(Co,Ni)Se-2/C　catalyst.　This　work　will　trigger　a　solid　step　for　the　design　of　highly-efficient　OER　electrocatalysts.　(C)　2022,　Dalian　Institute　of　Chemical　Physics,　Chinese　Academy　of　Sciences.　Published　by　Elsevier　B.V.　All　rights　reserved.