Abstract: Bi₂SrCaCo₂O_δ and Bi₂Ca₂Co₂O_δ oxide thermoelectric materials were prepared by solid-state reactions.The effect of substitution Ca for Sr on ceramic preparation condition, electrical properties and crystal structure anisotropic were studied.Influence of sintering temperatures and doping content on microstructure as well as electrical properties of ceramics were investigated by XRD, SEM and a standard four probes method.The results indicate that the crystal structure of Bi₂Sr₂Co₂O_δ is not destroyed by Ca substitution on the Sr, and also shows layered grown obviously, c-axis preferred orientation obviously.The c-axis size decreased due to the replacement of Sr with Ca.The sintering temperatures increase with the substitution Ca for Sr.Temperature dependence of electric resistivity showed obviously semiconductive behaviors.