The effects of BaCu(B2O5) (BCB) additions on the sintering temperature and microwave dielectric properties of Ba3Ti5Nb6O28 ceramic have been investigated using dilatometer, X-ray diffraction, scanning electron microscopy and dielectric measurement. The pure Ba3Ti5Nb6O28 ceramic shows a high sintering temperature (similar to 1250 degrees C) and good microwave dielectric properties as Q x f of 11,400 GHz, epsilon(r) of 37.0, tau(f) of -8 ppm degrees C-1. It was found that the addition of BCB to Ba3Ti5Nb6O28 could lower the sintering temperature from 1250 to 925 degrees C. The reduced sintering temperature was attributed to the BCB liquid phase. The addition of BCB also enhanced the microwave dielectric properties to Q x f of 19,191 GHz, epsilon(r) of 38.2, tau(f) of 12 ppm degrees C-1. (C) 2008 Elsevier B.V. All rights reserved.