The　crystal　structure　and　dielectric　properties　of　CaO-Al2O3-SiO2　(CAS)/Sr0.6Ba0.4Nb2O6　(SBN40)　glass-ceramics　prepared　by　the　sintering　method　were　investigated.　With　the　increase　of　SBN40　content,　the　density　of　CAS/SBN40　glass-ceramics　gradually　increases,　while　the　temperature　required　to　obtain　the　highest　density　slightly　declines　at　first,　and　then　sharply　rises　when　the　SBN40　content　is　above　70%　(in　mass,　the　same　below).　The　major　phase　gradually　transforms　from　SiO2,　CaNb2O6　to　tungsten　bronze　phase　SBN　with　the　increase　of　SBN40　content.　Single　phase　SBN　can　be　formed　when　the　SBN40　content　reaches　90%.　At　the　same　time,　the　dielectric　constant　increases　gradually　at　first　for　100　kHz,　and　then　rapidly　increases　when　the　SBN40　content　increases,　which　is　relative　to　the　variation　of　the　phase　constitution.　10%　CAS/90%　SBN40　glass-ceramics　with　a　dielectric　constant　of　963　is　a　new　relaxor　ferroelectric　material　that　exhibits　an　obvious　diffuse　dielectric　peak　at　around　80°C.