The　photocatalytic　activity　of　polymeric　carbon　nitride　(g-C3N4)　strongly　depends　on　its　electronic　structure　which　is　highly　sensitive　to　the　preparation　methods.　To　design　the　photocatalysts　with　efficient　charge　separation　and　transfer　property,　here　we　report　a　new　ethylenediamine　(EDA)　induced　gas-solid　grafting　method　which　enables　the　asymmetric　modification　of　g-C3N4　featuring　the　aromatization　at　the　terminal　of　melon　motifs.　The　obtained　terminal-aromatized　g-C3N4　(Ar-C3N4)　exhibits　an　improved　visible-light-driven　photocatalytic　activity　in　versatile　two-electron　reduction　reactions,　outperforming　the　pristine　g-C3N4　by　15.4　and　6.6　folds　respectively　in　hydrogen　evolution　and　hydrogen　peroxide　production.　Theoretical　and　experimental　results　demonstrate　the　intensified　asymmetry　of　p-electron　distribution　in　the　resulting　material,　which　provides　significantly　improved　driving　force　to　guide　the　efficient　separation　of　photogenerated　e-h　pairs　and　enhance　the　charge　carrier　mobility　compared　to　its　symmetric　counterpart.