Glass-ceramic materials of the CaO-B 2 O 3 -SiO 2 (CBS) system added with various amounts of Al 2 O 3 have been prepared by conventional melting and heat treated crystallization method. The effects of Al 2 O 3 on the sintering characterization and dielectric properties have been investigated. With increasing the Al 2 O 3 content, the bending and stretching vibrations in [SiO 4 ] 2-became weak. XRD patterns of samples with C3 wt% Al 2 O 3 introduce cyclowollastonite (a-CaSiO 3 ) as single crystallized phase of sintered glass-ceramics. It is found that the optimal sintering temperature for this glass ceramics is 800°C for 30 min, and the sinterability was obviously improved by Al 2 O 3 additive. CBS glass ceramics sample with 5 wt% Al 2 O 3 achieved the best sintering characterization and dielectric properties (e r & 7, tan d = 1.9 9 10 -3 at 1 MHz), which is proposed to be suitable for LTCC application.