Lead‐free barium stannate titanate ceramics doped with 2 wt% of B2O3B2O3 were prepared via a solid state sintering. The optimum condition for the preparation was carried out. Properties of the lead free material were characterized by various methods. The high dielectric constant>14000 with low tan δ 0.040 was observed at 34° C for the samples prepared at the optimum condition. Plots of dielectric permittivity as a function of temperature showed that the ceramics exhibit a diffuse ferroelectric‐paraelectric phase transition. The dielectric constantwas also measured as a function of electric field. The dielectric‐electric field measurement indicated that this material exhibits a high tunability. In addition, mechanical property such as hardness was investigated. Relation between grain size and hardness of the ceramics was found to obey the Hall‐Petch equation: Hv = 0.07+12.9G−12.