In this study, we investigated the effect of sintering temperature on densification, grain size, conductivity and dielectric properties of Sr_1-x(Na_0.5Bi_0.5)_xBi₂Nb₂O₉ ceramics, prepared by hydrothermal method. Pellets were sintered at different temperatures. Density increased with sintering temperature, reaching up to 96% at 800 ℃. A grain growth was observed with increasing sintering temperature. Impedance spectroscopy analyses of the sintered samples at various temperatures were performed. Increase in dielectric constant and in Curie temperature with sintering was discussed. Electrical conductivity and activation energy were calculated and attributed to the microstructural factors.