The effect of variations of the Zr:Sn ratio on the microstructure and electric properties of lead lanthanum zirconate stannate titanate (PLZST) antiferroelectric ceramics were investigated. The precursor powders were synthesized by the modified coprecipitation method and all the samples were pure perovskite phase in the XRD patterns. The ceramics sintered at 1100°C exhibited the highest relative density. With the increasing of Sn 4+ content, the grain size of the ceramics was decreased in the SEM and the maximum dielectric constant and the corresponding temperature were decreased. The P–E hysteresis loops indicated that it is helpful to steady the antiferroelectric phase by increasing Sn 4+ content.