We report O and Ca K-edges x-ray absorption near edge structure (XANES) spectra of Ba 1−x Ca x TiO 3 (x = 0.01 and 0.08), BaTiO 3 and CaTiO 3 and the electronic structure of Ba 0.875 Ca 0.125 TiO 3 obtained by first-principles calculation. The characteristic features in the O K-edge XANES spectra of these ferroelectric perovskites are influenced by the Ca concentration. They differ substantially from those of the reference TiO 2 . The O K-edge spectra suggest that the combination of the alkaline-earth-metal oxides, CaO and/or BaO, with TiO 2 enhance the effective charge of the O ions. Thus, a large dipole moment may result from the displacement of the Ti ion from the centre of the TiO 6 octahedron leading to collective displacement of Ti ions through attractive dipole-dipole couplings and may give rise to ferroelectricity. In the Ca K-edge XANES spectra there is a pre-edge feature similar to those found in other 3d transition-metal perovskites, which may provide information about hole doping.