A proton conducting material, Ba3Ce(PO4)(3), was synthesized by coprecipitation, with a calcination temperature of 1100 degrees C and a dwell time 4 h. The obtained particle size was around 200-500 nm. Proton conduction of Ba3Ce(PO4)(3) was studied by ac impedance spectroscopy under oxygen, air, nitrogen, and hydrogen atmospheres and by electromotive force measurements of dry hydrogen concentration cells. The conductivities of Ba3Ce(PO4)(3) in dry and wet 4 vol % hydrogen was around 4.04 x 10(-5) and 1.46 x 10(-4) S/cm at 600 degrees C, respectively. The proton transference number was similar to 0.8 in dry hydrogen concentration cells at 600 degrees C. Based on the conductivity and transference number measurement results, Ba3Ce(PO4)(3) is considered a promising candidate for an intermediate temperature proton conductor. (C) 2007 The Electrochemical Society.