Ceramics based on zirconium carbonitride belongs to the class of Ultra-High Temperature Ceramics and has a set of promising properties, such as high hardness and strength, resistance to aggressive chemicals, high melting temperatures and oxidative resistance. Due to the complication of the structure when creating ZrCN-ZrO₂ ceramics, it becomes possible to qualitatively improve the properties of the material, namely to take a significant step in solving the key problem found in materials of this class: their low crack resistance. In the course of this work, ceramic samples of ZrCN-ZrO₂ were obtained with various stoichiometry by hot pressing and spark plasma sintering. It was established that during hot pressing, reduced porosity in the samples is achieved, within 2%. It is observed that with an increase in the ZrO₂ content, a decrease in the porosity of materials is achieved. For consolidated samples, it was found that when the carbonitride is formed, the hardness of the materials increased to values of 18 GPa with an increase in the ratio of N/(C+N) in the studied materials and a decrease in porosity. A similar situation is observed for Young’s modulus, showing an increase of up to 427 GPa. When examining the crack resistance of ZrCN-ZrO₂ ceramics, it was found that with an increase in the ZrO₂ content, the crack resistance of materials increases to the values of 4.3 MPa·m^1/2. When studying oxidative behavior, it was found that the samples underwent active oxidation from a temperature of 800 ℃. With an increase in the ZrO₂ content in the material under study, an increase in the oxidative resistance of the samples was observed as a result of the peroxidation process of cubic zirconium dioxide. Due to the complicated structure of ceramics based on zirconium carbonitride, the mechanical properties increased along with the oxidative resistance of the materials.