Self-nitrogen-doped　porous　biochar　derived　from　kapok　fibers　possesses　unique　structure　and　excellent　electrochemical　performance.　In　this　study,　one-step　pyrolysis　method　was　introduced　to　prepare　porous　biochar　from　kapok　fibers,　and　effect　of　pyrolysis　temperature　on　structure　and　electrochemical　performance　of　the　porous　biochar　was　investigated.　It　was　found　that　pyrolysis　temperature　played　an　important　role　in　determining　microstructure　of　the　biochar.　At　the　pyrolysis　temperature　of　750　°C,　the　as-prepared　biochar　(CKF-750)　represented　a　largest　specific　surface　area　of　1125.7　m2　g−1　and　pore　volume　of　0.7130　m3　g−1,　and　hence　brings　CKF-750　a　highest　specific　capacitance　of　283　F　g−1　at　a　current　density　of　1　A　g−1　in　a　6　mol　L−1　KOH　electrolyte.　Furthermore,　the　cycle　stability　of　CKF-750　was　wonderful,　and　the　specific　capacitance　retained　almost　constant　after　10000　cycles.　Therefore,　the　pyrolysis　temperature　of　750　°C　is　optimal　for　the　preparation　of　porous　biochar　as　an　outstanding　electrode　material　for　supercapacitor.　©　2018