Ba2SrCe2TbO9 ceramic (abbreviated B2SC2T) was prepared using solid-state reaction method. The crystal structure and defect chemistry of B2SC2T were investigated using X-ray diffraction (XRD), electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS). XRD results indicate that B2SC2T ceramic has a triclinic perovskite structure. EPR and XPS show that Ce ions exist as Ce4+, and Tb ions coexist in the mixed valence states of Tb3+ and Tb4+.