The　insufficient　durability　of　Pt-based　catalysts　and　the　sluggish　kinetics　of　oxygen　reduction　reaction　(ORR)　is　hampering　the　development　of　proton　exchange　membrane　fuel　cells　(PEMFCs)　for　commercialization.　Herein,　a　single　atom　Ti-modified　activated　nitrogen-doped　porous　carbon　(Ti-a-NPC)　is　designed　to　equalize　O2-activation/*OH-removal　through　regulating　the　charge　rearrangement　of　ultra-small　L12-Pt3Co　for　efficient　and　durable　oxygen　reduction.　The　Ti　single-atom　modified　in　the　surface/pore　of　Ti-a-NPC　can　anchor　the　Pt-based　intermetallic　nanoparticles　(NPs)　not　only　guarantees　Pt-based　intermetallics＇　ultra-fine　size　(approximate　to　2.62　nm)　but　also　maintains　Pt-based　intermetallics　during　ORR　process.　The　enhanced　catalyst　(L12-Pt3Co/Ti-a-NPC)　achieves　11-fold　mass　activity　(1.765　A　mgPt-1)　compared　to　commercial　Pt/C.　Notably,　after　30　000　cycles　of　accelerated　durability　tests,　the　mass　activity　of　the　L12-Pt3Co/Ti-a-NPC　only　decreased　by　3.7%,　while　that　of　commercial　Pt/C　decreased　by　37.1%.　Rationalized　by　theoretical　simulation,　the　introduction　of　Ti　atoms　can　form　charge　channels　between　L12-Pt3Co　NPs　and　Ti-a-NPC,　accelerating　the　charge　transfer　in　the　ORR　process.　Furthermore,　the　charge　of　L12-Pt3Co　will　accumulate　to　Ti　atoms　and　buffer　the　electron　transfer　of　L12-Pt3Co　to　the　N　atoms,　thus　optimizing　the　adsorption　performance　of　the　active　site　to　the　oxygen-containing　intermediate　and　improving　the　intrinsic　activity　of　the　catalyst.　The　single-atom　Ti　synergizes　with　the　confinement　effect　of　Ti-a-NPC　not　only　restricting　the　size　increase　of　Pt-based　intermetallics　during　the　ordering　process　(average　size　2.6　nm)　but　also　inhibiting　the　shedding　and　migration　of　Pt-based　intermetallics　under　fuel　cell　operating　conditions.　The　charge　of　ultra-small　L12-Pt3Co　is　regulated　by　single　atom　Ti　to　equalize　O2-activation/*OH-removal　for　efficient　oxygen　reduction.　image