Two-dimensional　(2D)　materials　with　high　anisotropic　properties,　such　as　black　phosphorus　and　ReS2,　show　amazing　potential　for　applications　in　future　nano　electronic　and　optoelectronic　devices.　However,　degradation　of　black　phosphorus　under　ambient　conditions　and　the　expensiveness　of　Re　block　their　application.　In　this　study,　another　layered　material,　KP15,　that　has　highly　anisotropic　properties　was　successfully　prepared.　The　detailed　crystal　structure　and　electron-density　distribution　calculation　reveal　that　KP15　exhibits　an　anisotropic　layered　structure　with　two　rows　of　P　tubes　connected　by　K　atoms　that　are　antiparallel　in　a　single　layer.　Outstanding　chemical　stability,　angular　dependence　of　the　Raman　response,　excitation,　and　exciton　emission　at　room　temperature　have　been　found　in　exfoliated　KP15　nanoribbons.　Importantly,　the　exciton　emission　at　room　temperature　suggests　the　existence　of　a　large　exciton　binding　energy.　Our　results　indicate　that,　because　this　layered　material,　KP15,　has　high　anisotropic　properties　and　ultrachemical　stability　and　is　derived　from　abundant　raw　materials,　it　has　great　potential　for　applications　in　optoelectronic　devices.