Novel glass–free low temperature firing microwave dielectric ceramics Li2CeO3 with high Q prepared through a conventional solid-state reaction method had been investigated. All the specimens in this paper have sintering temperature lower than 750°C. XRD studies revealed single cubic phase. The microwave dielectric properties were correlated with the sintering conditions. At 720°C/4 h, Li2CeO3 ceramics possessed the excellent microwave dielectric properties of εr = 15.8, Q × f = 143 700 (GHz), and τf = −123 ppm/°C. Li2CeO3 ceramics could be excellent candidates for glass-free low-temperature co-fired ceramics substrates.