Dandelion　seeds　(DSs)　have　the　advantages　of　high　nitrogen　content,　low　cost　and　easy　availability　and　thus　are　ideal　carbon　precursors　for　fabricating　carbon　nanomaterials.　Herein,　this　paper　prepared　a　carbon　nanosheet　material　by　one-step　carbonizing　DSs　with　KOH　activation　(self-doped-nitrogen　porous　carbon　nanosheets　(N-CNS))　and　without　KOH　activation　(unactivated　self-doped-nitrogen　porous　carbon　nanosheets　(N-UA-CNS)),　which　could　dope　nitrogen　atoms　directly　into　carbon　materials　without　additional　processes.　Scanning　electron　microscopy(SEM)　images　and　X-ray　diffraction(XRD)　patterns　both　showed　that　N-CNS　was　of　macro-porous　structure,　and　beneficial　for　microorganisms＇　growth.　The　Brunauer　Emmett　Teller(BET)　surface　area　of　N-CNS　was　2107.5　m(2)　g(-1),　which　was　much　higher　than　that　of　N-UA-CNS.　After　carbon　clothes　were　modified　by　the　obtained　materials,　the　internal　resistance　of　both　N-CNS-modified　carbon　cloth　(N-CNS-CC)　and　N-UA-CNS-modified　carbon　cloth　(N-UA-CNS-CC)　was　greatly　reduced　and　was　found　to　be　only　2.7　omega　and　4.0　omega,　respectively　which　are　all　significantly　smaller　than　that　of　blank　carbon　cloth　(65.1　omega).　These　electrodes　were　assembled　in　microbial　fuel　cells　(MFCs)　as　anode,　and　the　operation　experiments　showed　that　the　N-CNS　modification　shortened　start-up　time,　improved　output　stability　and　increased　maximum　output　voltage　significantly.　The　maximum　power　density　of　N-CNS-CC　MFC　was　1122.41　mW　m(-2)　which　was　1.3　times　of　that　of　N-UA-CNS-CC　MFC　and　1.6　times　of　that　of　CC　MFC.　The　results　demonstrated　that　N-CNS　was　an　ideal　modification　material　for　fabricating　MFC　anodes　with　simple　preparation　process　and　low　cost.