Graphitic　carbon　nitride　(g-C3N4)-based　photocatalysts　are　promising　for　photocatalytic　water　splitting　to　produce　clean　solar　fuels　due　to　their　low　cost,　suitable　band　structure　and　excellent　photocatalytic　performance.　This　review　focuses　on　the　state-of-the-art　progress　of　the　strategies　for　modifying　g-C3N4-based　photocatalysts　toward　efficient　photocatalytic　water　splitting.　In　particular,　we　high-light　the　importance　of　interfacial　engineering　and　nanostructural　control　to　facilitating　charge　separation　and　migration.　Other　strategies　including　doping　and　defect　engineering　are　also　concisely　discussed.　Finally,　the　perspectives　on　the　challenges　and　future　development　of　g-C3N4-based　photocatalysts　are　presented.