Novel microwave dielectric ceramics in the Li2MnO3 system with high Q prepared through a conventional solid-state route had been investigated. All the specimens exhibited single phase ceramics sintered in the temperature range 1140 degrees C-1230 degrees C. The microwave dielectric properties of Li2MnO3 ceramics were strongly correlated with sintering temperature and density. The best microwave dielectric properties of epsilon r=13.6, Qxf=97000 (GHz), and f=-5.2ppm/degrees C could be obtained as sintered at 1200 degrees C for 4h. BaCu(B2O5) (BCB) could effectively lower the sintering temperature from 1200 degrees C to 930 degrees C and slightly induced degradation of the microwave dielectric properties. The Li2MnO3 ceramics doped with 2wt% BaCu(B2O5) had excellent dielectric properties of epsilon r=11.9, Qxf=80600 (GHz), and f=0ppm/degrees C. With low sintering temperature and good dielectric properties, the BCB added Li2MnO3 ceramics are suitable candidates for LTCC applications in wireless communication system.