Crystalline structure, microstructure and dielectric properties for Ba(Ti1-yCey)O-3 (0less than or equal toyless than or equal to0.5) ceramics have been studied. Dense ceramics with the relative density higher than 95% and grain size of 0.7-1.5 mum have been obtained. The limit of the solid solubility is determined as y = similar to0.3 by the X-ray diffraction, SEM, and dielectric properties measurements. The crystalline symmetry is tetragonal for the sample with y = 0.02 and cubic for y greater than or equal to 0.06 at room temperature, and the unit cell increases with increasing Ce content in the solid solution range. Correspondingly, the dielectric response exhibits three dielectric peaks for y = 0.02, and one pinched dielectric peak with ferroelectric relaxor behavior for y less than or equal to 0.06. (C) 2003 Kluwer Academic Publishers.