A　new　barium　aluminoborate,　Ba2Al4B6O17,　has　been　synthesized　by　the　high　temperature　solution　reaction　at　780　degrees　C.　The　single-crystal　XRD　analysis　shows　that　it　crystallizes　in　triclinic　space　group　P　(1)　over　bar　with　a　=　8.9601(5),　b　=　9.1835(6),　c　=　10.6574(7)　angstrom,　alpha　=　95.050(6)degrees,　beta　=　111.569(5)degrees,　gamma　=　90.280(6)degrees,　V　=　811.71(9)　angstrom(3),　Z　=　2,　M-r　=　719.46,　D-c　=　2.944　g/cm(3),　mu　=　5.127　mm(-1),　F(000)　=　660,　R　=　0.0361　and　wR　=　0.0855　for　3846　observed　reflections　and　262　variables.　This　compound　represents　a　new　structure　that　features　a　three-dimensional　[Al4B6O17](n)(4n-)　framework　constructed　by　AlO4　tetrahedra,　BO3　triangles,　and　B2O54-　groups　composed　of　two　corner-sharing　BO3　triangles,　with　intersecting　open　channels　accommodating　Ba2+　cations.　It　melts　incongruently　at　849　degrees　C.　The　existence　of　BO3　groups　is　confirmed　by　FT-IR　and　Raman　spectra.　The　insulating　nature　with　an　optical　band　gap　of　about　3.50　eV　is　revealed　by　UV-VIS　diffuse　reflectance　spectrum.　Band　structure　calculations　indicate　that　it　is　an　indirect　band　material.