This article presents an investigation of the influence of modification of Al2O3–(Ce-TZP) with alkaline earth elements Ca+2 and Mg+2 on the phase composition, microstructure, and strength characteristics of composites. It is established that modification of Mg+2 compositions leads to a decrease in the strength parameters of composites, while introduction of Ca+2 contributes to an increase in the strength parameters of the respective composites owing to aggregation of effects of transformational and dispersive hardening. The obtained high-strength composites can be applied as constructional materials in engineering and medicine.