The composition and microstructure, sintering temperature and dielectric properties of Ba4[Sm1-x(Nd0.8Bi0.2)x]28/3Ti18O54（x=0.15~0.9）system ceramics were comprehensively characterized and studied by XRD, SEM, etc. When x=0.45, excellent dielectric properties of a high dielectric constant and temperature coefficient of resonant frequency of approximately 0 were obtained for the ceramics sintered at 1 320 ℃: εr=90.22,Q×f=7 192 GHz,τf=-1.39 μ℃-1. With the increase of x, that is BNBT phase increase, the sintering temperature decreased from 1 450 ℃ to 1 300 ℃, the sintering characteristics was also improved.