The crystal structure and electrical properties of SrTiO₃ with addition of 50 mol% SnO2 was studied. Samples were prepared using conventional solid-state reaction route. The results indicate that Sn doped SrTiO₃ was single phase with cubic phase and space group Pm-3m after final sintering temparture at 1400°C. Two semicircular arcs clearly observed in Z" versus Z' plots for SrTi0.5Sn0.5O3 semicircles associated with bulk relaxation processes and grain boundary effect. The heterogeneity of sample was observed form Z' and M" spectroscopic plot. The highest dielectric constant is observed at much higher temperature which nearly 2000 at low frequency measurement.
