A simple coprecipitation technique had been successfully applied for the preparation of pure ultrafine single-phase CaBi 2 Ta 2 O 9 (CBT). Ammonium hydroxide and ammonium oxalate were used to precipitate Ca 2+ , Bi 3+ and Ta 5+ cations simultaneously. No pyrochlore phase was found while heating powder at 800 °C and pure CaBi 2 Ta 2 O 9 phase was found to be formed by XRD. Particle size and morphology was studied by transmission electron microscopy (TEM). The room temperature dielectric constant at 1 kHz is 100. The ferroelectric hysteresis loop parameters of these samples were also studied.