The effects of glass additions on the microwave dielectric properties and the microstructures of Ba 2 Ti 9 O 2 0 ceramics were investigated. The simple glasses B 2 O 3 and SiO 2 and the commercial glass PbO-B 2 O 3 -SiO 2 (PBS) were selected as liquid phase sintering aids to lower the sintering temperature of Ba 2 Ti 9 O 2 0 ceramics. With glass additions, the sintering temperatures can be effectively lowered. The dielectric properties of Ba 2 Ti 9 O 2 0 ceramics with glass additions are strongly dependent on the densification, the microstructure, and the reaction between glasses and ceramics. Ba 2 Ti 9 O 2 0 ceramics without glass addition sintered at 1380 o C has a dielectric constant r = 38.8, a quality factor Q = 7200 at 6.0 GHz, and a temperature coefficient of resonant frequency τ f = 4 ppm/ o C. Among these glasses, 5 wt% B 2 O 3 added Ba 2 Ti 9 O 2 0 can be sintered to achieve theoretical densities of 96 and 95% at 1100 and 1200 o C, and gives r values of 36.5 and 36 together with Q values of 3200 and 6700 (at 6 GHz), respectively. Results of XRD analysis and scanning electron microscopy are also presented.