The glass composition CaO-Al2O3-B2O3-SiO2 as an alternative glass composition, and commercial α-Al2O3 as a ceramic material was used. The structure of the glass was analyzed by infrared spectra; the glass-ceramics thermal expansion coefficient was measured by dilatometer, the phase separation of the sample was investigated by scanning electron microscope and the component of phase was analyzed by X-ray. The results show that [BO3] increases and [BO4] decreases in the glass structure with the increasing of B2O3 content added into CaO-Al2O3-B2O3-SiO2 glass. The relative density and dielectric constant (εr) are considerably decreased with the addition of amount of B2O3. Excellent microwave dielectric properties of 1MHz, εr = 8.0 and tanδ=0.003 are obtained by adding 10 wt% B2O3 to glass-ceramic and sintering at 875°Cfor 30 min.