Microwave dielectric properties of Li-containing orthorhombic compounds with the composition of MLi2Ti6O14 (M=Ba and Sr) were investigated. The ceramics were synthesized by the conventional solid-state reaction route. The optimized sintering temperatures for the BaLi2Ti6O14 and SrLi2Ti6O14 ceramics are 1025 degrees C and 1000 degrees C, respectively. Favorable microwave dielectric properties were obtained with moderate epsilon(r) of 31.7 and 33.6, quality factor Qxf values of 23300 (at 7.3GHz) and 8700GHz (at 6.8GHz), and low-temperature coefficient of resonant frequency ((f)) values of -15.4 and -2.7ppm/degrees C for BaLi2Ti6O14 and SrLi2Ti6O14 ceramics, respectively. The addition of BaCu(B2O5) can effectively reduce the sintering temperature below 930 degrees C without degrading the microwave dielectric properties. Compatibility with Ag electrode indicates these materials could be applied to low-temperature cofired ceramic devices.