The heterogeneous CaB6–TiB2 powder mixtures were synthesized by reducing the mixture of TiO2 and CaCO3 with boron carbide in vacuum at 1400 – 1650°C. Reaction hot pressing was conducted according to the following regime: 1500°C (synthesis in vacuum) – 1900°C (pressing in Ar). As a result of synthesizing CaB6–TiB2 at mass ratio of 1:1 and 1600°C followed by isothermal soaking for 1 hour, a heterogeneous mixture was obtained containing crystalline phases of CaB6 and TiB2 with the residual B4C impurity (0.5 wt. %). The powder particles represent grains measuring 1 – 3 μm in diameter and containing two phases CaB6 and TiB2 in the form of crystallites measuring 0.1 – 1.0 μm in diameter uniformly distributed throughout the particle volume.