Two-dimensional　materials　with　high　anisotropic　optical　properties　and　high　exciton　binding　energy　offer　great　advantages　for　developing　nanostructure　electronic　and　optoelectronic　devices.　However,　conduction　electron　scattering　from　surface　defects　caused　by　the　short　width　and　length　of　the　channel　layer　in　semiconductor　devices　blocks　their　application.　In　this　research,　NaP15　is　considered　as　another　kind　of　layered　material　with　high　anisotropic　properties.　Its　anisotropic　layered　structure　was　revealed　by　its　detailed　crystal　structure　and　electron-density　distribution　calculation,　which　showed　two　antiparallel　rows　of　pentagonal　P　tubes　interacting　with　weak　Coulomb　forces　and　four　adjacent　P　tubes　in　one　unit　coordinated　by　Na　atoms.　The　outstanding　chemical　stability,　angle-resolved　polarized　and　temperature-dependent　Raman　spectroscopy,　and　neutral　exciton　emission　caused　by　surface　state　excitation　in　exfoliated　NaP15　nanoribbons　at　room　temperature　clearly　reveal　its　one-dimensional　layered　property.　The　distinctive　structural　characteristics　and　electronic　properties　render　it　with　substantial　potential　for　applications　in　the　realm　of　polarimetric　detectors.