The　Oxygen　reduction　reaction　(ORR)　plays　an　important　role　in　fuel　cells,　but　the　synthesis　of　efficient　and　low-cost　catalysts　remains　challenging.　We　report　the　synthesis　of　ultra-small　Mo2C　nanoparticles　with　an　average　size　of　1.5　nm　embedded　in　a　N-doped　holey　carbon　(NHC)　matrix　by　employing　self-assembled　macrocycle　cucurbit[6]uril　(CB[6])　and　melamine　as　carbon　precursors.　The　interaction　between　Mo　precursors　and　CB[6]　effectively　prevented　the　aggregation　of　Mo2C　NPs　during　the　pyrolysis　procedure.　Besides,　the　holey　structural　carbon　has　a　larger　electrocatalytic　activity　area　and　improves　mass　transfer　efficiency　and　charge　transfer　rate.　The　NHC　features　abundant　defective　sites　and　thus　effective　anchoring　and　electronic　regulation　for　Mo2C　nanoparticles.　The　electrochemical　oxygen　reduction　activity　of　Mo2C/NHC　is　comparable　to　that　of　noble　metal　Pt/C　benchmark　catalyst　with　an　initial　potential,　half-wave　potential　and　limiting　current　density　of　0.95　V,　0.84　V　and　5.0　mA　cm−2,　respectively.　Mo2C/NHC　shows　a　good　long-term　durability　during　25　h　chronoamperometry.　©　2022　Wiley-VCH　GmbH.