Oxygen　electrocatalysis,　especially　oxygen　evolution　reaction　(OER),　is　a　central　process　during　the　actual　application　of　rechargeable　metal-air　battery.　It　is　still　challenging　to　develop　ideal　electrocatalysts　to　substitute　the　commercial　noble　metal-based　materials.　In　this　work,　we　have　constructed　a　new　material,　CoP　nanoparticles,　which　are　encapsulated　by　a　biomolecule-derived　N,　P-codoped　carbon　nanosheets　via　a　simple　and　facile　one-step　strategy.　The　as-prepared　material　releases　a　high　electrocatalytic　activity　and　stability　for　OER,　with　an　overpotential　of　310　mV　to　achieve　10　mA/cm(2)　in　1　M　KOH.　Importantly,　we　found　that　the　phosphoric　acid　can　not　only　introduce　phosphorus　dopant　into　2D　N-doped　carbon　nanosheets　and　play　a　role　of　pore-forming　agent,　but　also　participate　in　the　formation　of　active　center　(cobalt　phosphide).　Moreover,　the　coverage　of　N,　P-doped　carbon　can　prevent　the　CoP　nanoparticles　from　corrosion　under　the　harsh　reaction　medium　to　achieve　high　and　stable　activity.　We　believe　that　our　strategy　can　offer　a　novel　pathway　to　synthesize　new　transition　metal-based　catalysts　for　electrocatalysis　or　other　heterogeneous　catalysis.