Single-atom　catalysts　with　uniform　metal　active　sites　show　potential　for　selectivity　control.　However,　their　application　to　high-temperature　propane　dehydrogenation　remains　challenging.　Here　we　develop　a　highly　stable　and　efficient　single-atom　catalyst　for　propane　dehydrogenation　that　is　based　on　Ru　single　atoms　on　nitrogen-doped　carbon　(Ru-1/NC).　The　turnover　frequency　of　Ru-1/NC　is　at　least　three　times　higher　than　that　of　nanoparticle　counterparts,　resulting　in　propylene　selectivity　of　around　92%　with　a　lower　deactivation　rate　at　560　&　DEG;C.　Experimental　and　density　functional　theory　studies　reveal　the　important　role　of　peripheral　N　species　around　the　Ru-1　centre.　The　inner-shell　N　stabilizes　the　atomically　dispersed　Ru　to　inhibit　structure-sensitive　propane　cracking,　while　the　outer-shell　N　promotes　electron　accumulation　at　the　Ru-1　centre,　inducing　a　significant　charge　repulsion　between　Ru-1　and　propylene　to　facilitate　its　desorption.　The　combined　functions　of　inner-shell　and　outer-shell　N　species　at　single-atom　Ru　sites　contribute　to　the　high　efficiency　of　Ru-1/NC.