We　studied　the　excitonic　states　of　KP15　nanowires,　which　have　high　carrier　mobility　and　in-plane　anisotropic　electrical　and　optical　properties.　Power,　thickness,　and　temperature-dependent　photo-luminescence　(PL)　measurements　were　carried　out.　We　found　two　neutral　exciton　emissions　from　KP15　nanowires.　The　high　energy　emission　(1.83　eV)　seems　to　have　been　produced　by　the　surface　state,　and　the　lower　one　(1.67　eV)　may　have　been　produced　by　the　original　crystal　structure　of　KP15　.　The　KP15　nanowires　also　exhibited　a　large　exciton　binding　energy　(98　meV),　which　is　one　order　of　magnitude　greater　than　those　of　common　semiconductors.　These　properties　make　KP15　nanowires　an　interesting　material　for　electrical　and　optical　applications.