Two-dimensional　(2D)　materials　represented　by　graphene　show　numerous　attractive　electronic,　optical,　mechanical,　and　thermal　properties.　Especially,　the　extraordinary　electronic　and　optical　properties　make　2D　materials　promising　candidates　for　photodetectors　to　replace　traditional　ones　that　fails　to　meet　the　growing　demands　of　many　fields　such　as　high　frequency　communication,　national　security,　novel　biomedical　imaging　and　so　on.　However,　several　challenges　must　be　overcome　before　the　realization　of　commercially　viable　2D　materials-based　photodetectors,　such　as　the　low　photoresponsivity　of　intrinsic　graphene　due　to　its　low　optical　absorption　coefficient　and　zero　bandgap　induced　high　recombination　ratio　of　photo-excited　carrier,　the　poor　carrier　mobility　of　transition-metal-dichalcogenides　(TMDCs),　the　instability　and　the　difficulties　in　preparation　of　black　phosphorus　(BP)　film.　In　the　past　few　years,　numerous　efforts　have　been　made　persistently　to　improve　the　performance　of　the　devices　and　several　strategies　were　demonstrated　to　be　effective.　Here,　we　reviewed　the　latest　advances　of　photodetectors　which　are　based　on　typical　2D　materials　including　graphene,　TMDCs,　BP,　hexagonal　boron-nitride　(h-BN)　as　well　as　new　layered-material　(GaS,　GaSe,　InSe).　We　discuss　the　experimental　challenges　and　describe　the　advances　of　different　approaches　by　dividing　them　into　four　categories　regarding　the　detection　wavelength　ranges　including　ultraviolet　(UV),　visible　to　near-infrared　(Vis-NIR),　mid-　to　far-　infrared　(MIR-FIR),　and　terahertz　(THz).　(C)　2017　Elsevier　B.V.　All　rights　reserved.