Semiconductor　photocatalysis　via　sunlight-driven　photoredox　reactions　to　directly　convert　solar　energy　into　chemical　energy　or　to　mineralize　organic　pollutants,　is　regarded　as　a　long-term　solution　to　address　the　global　energy　and　environmental　problems.　Recently,　graphitic　carbon　nitride　(g-C3N4),　a　polymeric　semiconductor　has　been　widely　used　as　a　low-cost,　stable　and　metal-free　visible-light-active　photocatalyst　in　the　sustainable　utilization　of　solar　energy,　such　as　water　splitting,　organic　photosynthesis　and　environmental　remediation.　This　has　attracted　worldwide　attention　from　energy　and　environmental　relative　fields.　In　this　review,　some　recent　advances　in　g-C3N4,　photocatalysis　are　present,　including　the　theoretical　research　of　chemical　structure　and　features　of　g-C3N4,　metal/non-mental　doping　of　g-C3N4,　to　adjust　the　semiconductive　electronic　band　structure,　soft/hard　templates　assisted　the　synthesis　of　g-C3N4　nanoarchictures,　surface　modification　of　g-C3N4　to　overcome　the　high　kinetic　barrier　for　water　reduction/oxidation,　and　as　well　as　the　construction　of　g-C3N4,　based　heterojunctions　and　composite　photocatalysts　to　promote　the　separation　of　energy-wasteful　charge　recombination.　The　prospects　for　the　development　of　highly　efficient　g-C3N4　based　photocatalysts　are　also　discussed.