For the aim of low-temperature co-fired ceramic microwave components, sintering behavior and microwave properties (dielectric constant , quality factor Q, and temperature coefficient of resonant frequency ) are investigated in [BCZN] ceramics with addition of . The specimens are prepared by conventional ceramic processing technique. As the main result, it is demonstrated that the additives () show the effect of lowering of sintering temperature and improvement of microwave properties at the optimum additive content. The addition of 0.25 wt% lowers the sintering temperature to utilizing liquidphase sintering and show the microwave dielectric properties (dielectric constant = 75, quality factor = 572 GHz, temperature coefficient of resonance frequency ). The estimated microwave dielectric properties with addition (increase of , decrease of , shift of to negative values) can be explained by the observed microstrucure (sintered density, abnormal grain structure) and possibly high-permittivity (BZN) phase determined by X-ray diffraction.