In　this　work,　we　investigate　the　effect　of　peripheral　B　doping　on　the　electrocatalytic　nitrogen　reduction　reaction　(NRR)　performance　of　N-doped　graphene-supported　single-metal　atoms　using　density　functional　theory　(DFT)　calculations.　Our　results　showed　that　the　peripheral　coordination　of　B　atoms　could　improve　the　stability　of　the　single-atom　catalysts　(SACs)　and　weaken　the　binding　of　nitrogen　to　the　central　atom.　Interestingly,　it　was　found　that　there　was　a　linear　correlation　between　the　change　in　the　magnetic　moment　(&　mu;)　of　single-metal　atoms　and　the　change　in　the　limiting　potential　(U-L)　of　the　optimum　NRR　pathway　before　and　after　B　doping.　It　was　also　found　that　the　introduction　of　the　B　atom　suppressed　the　hydrogen　evolution　reaction,　thereby　enhancing　the　NRR　selectivity　of　the　SACs.　This　work　provides　useful　insights　into　the　design　of　efficient　SACs　for　electrocatalytic　NRR.