The　development　of　highly　efficient　and　inexpensive　carbon-based　catalysts　for　the　production　of　hydrogen　from　water　electrolysis　is　a　considerable　challenge　in　the　field　of　sustainable　energy　transformation.　Herein,　an　in　situ　N-,　P-　and　Ca-codoped　biochar　was　successfully　fabricated　from　animal　bone　by　thermal　treatment　at　800　°C.　This　in　situ　N-,　P-　and　Ca-codoped　catalyst　exhibits　high　atomic　contents　with　synergistic　effects　of　N,　P　and　Ca,　a　large　electrochemically　active　surface　area,　a　low　charge-transfer　resistance,　high　conductivity,　and　a　large　specific　area.　These　characteristics　lead　to　an　outstanding　hydrogen　evolution　reaction　(HER)　activity　and　good　stability　in　a　H2SO4　acidic　solution,　with　an　onset　potential　of　80±3　mV,　an　overpotential　of　162±3　mV　at　a　current　density　of　10　mA/cm2,　a　Tafel　slope　of　80　mV/dec,　and　an　exchange　current　density　of　52.5　µA/cm2,　which　are　comparable　to　or　even　better　than　those　of　synthetic　heteroatom-doped　or　transition　metal-doped　carbon-based　catalysts.　These　findings　demonstrate　that　animal　bone　is　a　useful　material　for　the　preparation　of　N-,　P-　and　Ca-codoped　carbon　materials　as　effective　electrocatalysts　for　the　HER.　©　2021