The influence of La2O3 and Tm2O3 co-doping on the dielectric properties and the temperature stability of BaTiO3 was investigated. BaTiO3 ceramics were prepared with the compositional formula of (Ba1-xLax)(Ti1-x/Tm-4-y(y))O-3. La2O3 and Tm2O3 co-doping in BaTiO3 mainly had effects on an increase in the dielectric constant and the temperature stability, respectively. The increase of La2O3 concentration and the decrease of Tm2O3 concentration in BaTiO3 resulted in a decrease of lattice parameter and tetragonality because La3+ ion substituting for Ba site is smaller than Ba2+ ion and Tm3+ ion substituting for Ti site is larger than Ti4+ ion. With the increase of La2O3 and the decrease of Tm2O3, the dielectric constant of BaTiO3 was enhanced in spite of the reduction of tetragonality. P-E hysteresis measurements revealed that this phenomenon was based on the improvement of remanent polarization with the increase of La2O3 concentration. The introduction of excess Tm2O3 in BaTiO3 suppressed the grain growth and BaTiO3 ceramics showed higher temperature stability due to the stable tetragonal structure and the small grain size with the increase of Tm2O3 concentration. (C) 2011 Elsevier B.V. All rights reserved.