Developing　new　strategy　to　efficiently　improve　the　photocatalytic　activity　of　graphitic　carbon　nitride　(g-CC3N4)　for　hydrogen　evolution　is　critical　for　its　application　in　solar　energy　utilization.　In　this　work,　an　innovative　selective　cation　replacement　process　is　developed　to　synthesize　copper　doped　g-C3N4　nanotubes　driven　by　the　ion-dipole　interaction　of　metal　ions　in　g-C3N4.　The　tri-s-triazine　units　may　act　as　stable　frameworks　in　the　sequential　cation　exchange　reaction　process,　which　subsequently　leads　to　the　formation　of　Cu　doped　g-C3N4　with　high　specific　surface　area　and　nanotube　structures.　The　obtained　g-C3N4　exhibits　greatly　enhanced　visible-lightdriven　hydrogen　evolution　of　3.02　mmol　h(-1)　g(-1),　which　is　about　13　times　higher　than　that　of　pristine　one.　Detailed　characterization　reveals　the　underlying　mechanism　of　the　improved　photocatalytic　performance　on　the　newly　developed　g-C3N4,　which　can　provide　valuable　guides　to　rationally　design　new　efficient　photocatalysts.