Two　novel　red　phosphors　KBaEu(XO4)3　(X　=　Mo,　W)　have　been　synthesized　by　high-temperature　solid-state　reactions　and　the　crystal　structures　were　determined　for　the　first　time.　Single-crystal　X-ray　diffraction　data　reveal　that　their　space　groups　are　C2/c.　The　crystalline　structure　is　constituted　of　K/BaO8　distorted　square　antiprisms　and　distorted　EuO8　polyhedra　which　form　chains　lying　along　the　c-axis　and　two　kinds　of　distorted　XO4　tetrahedra.　This　high　disorder　of　K/Ba　which　might　lower　the　crystal　field　symmetry　around　Eu3+　results　in　the　high　purity　of　red　emission　around　615　nm　originating　from　5D0　→　7F2　transition　under　near-ultraviolet　(NUV)　excitation.　With　increasing　temperature,　the　luminescence　of　KBaEu(XO4)3　(X　=　Mo,　W)　phosphors　decreases　almost　linearly　with　subtle　alteration　for　the　CIE　coordinate.　As　the　temperature　reaches　550　K,　the　red　emission　intensity　decreases　to　37.3%　and　50.7%　of　that　at　300　K　for　KBaEu(MoO4)3　and　KBaEu(WO4)3,　respectively.　The　analysis　of　the　decay　curves　of　the　5D0　→　7F2　emission　at　variable　temperatures　indicates　the　weak　cross　relaxation　and　non-radiative　energy　transfer　between　Eu3+　ions.　These　results　demonstrate　that　the　investigated　phosphors　are　attractive　for　application　in　high　power　NUV　excited　white　LEDs.　©　2017　The　Royal　Society　of　Chemistry.