Nitrogen-doped　carbon-based　dots　(N-CDs)　with　good　electrocatalytic　activity　for　oxygen　reduction　reaction　have　been　prepared　by　dehydrating　ethylenediaminetetraacetic　acid　with　hot　and　concentrated　sulfuric　acid.　The　as-prepared　N-CDs　are　graphite-based　nanosheets　with　an　average　lateral　size　of　similar　to　7　nm　and　a　mean　thickness　of　similar　to　1.7　nm.　The　N-CDs　possess　abundant　oxygen-containing　groups　and　emit　blue　fluorescence　under　365　nm　UV　light.　Furthermore,　the　as-prepared　N-CDs　can　be　well　deposited　on　graphene　through　a　hydrothermal　treatment,　and　show　outstanding　electrocatalytic　activity　for　the　oxygen　reduction　reaction.