Spintronics　addresses　the　spin　degree　of　freedom　of　electrons　as　an　analog　of　the　traditional　information　technology　approach　toward　the　charge　degree　of　freedom.　Two-dimensional　(2D)　materials　have　provided　a　new　platform　for　spintronics　since　the　successful　isolation　of　graphene　in　2004.　In　this　review,　we　discuss　the　recent　progress　of　chromium　tri-iodide　(Crl(3)),　phosphorene,　silicene,　germanene,　stanene,　animonene,　and　borophene　in　spintronics.　Among　these　2D　materials,　Crl(3)　has　intrinsic　magnetism,　while　the　others　are　single-element　2D　materials　(Xenes)　without　intrinsic　magnetism.　A　review　is　presented　of　works　based　on　different　research　methods,　including　experimental,　theoretical,　and　simulation　studies.　Various　morphologies　of　2D　materials　are　included,　such　as　monolayers,　bilayers,　nanoribbons,　heterojunctions,　and　nanoflakes　of　different　shapes.　The　effect　of　atomic　doping,　vacancies,　line　defects,　strain,　and　external　fields　is　also　summarized.　Among　the　properties　and　applications　of　these　materials,　the　spin　polarization,　spin/valley-dependent　resistance,　various　Hall　effects,　RKKY　interaction,　Rashba　effect,　and　topological　phase　are　the　most　widely　studied　topics.　Over　the　past　two　years,　various　novel　spintronics　devices　have　been　designed　based　on　2D　materials,　and　numerous　fundamental　functions　in　spintronics　have　been　realized.　Thus,　we　also　summarize　the　emerging　novel　devices　in　this　field.　Finally,　we　present　a　summary　of　the　remaining　challenges　and　possible　future　directions.