We show that fully dense nanocrystalline titanate ceramic could be obtained by full crystallization from glass which was prepared by a novel contactless solidification process. Through annealing above glass transition temperature T_g for prescribed duration, BaTi₂O₅ ceramic with grain size of 20–130 nm was successfully fabricated. The dependence of the nanoceramic’s dielectric constant and dissipation on frequency was investigated. The results show clearly that the dielectric constant of BaTi₂O₅ nanoceramic depends on average grain size in nanometer scale, and an optimal range of the grain size is found which exhibits greater dielectric constant than conventional microcrystalline ceramics. The as-fabricated ceramic also possesses lower dielectric dissipation, which can be mainly attributed to the presence of nanometer-sized grains.