This paper provides a detailed study of the thermoelectric properties of SiC/A1N composites in a wide temperature range. Evaluation of thermal stress durability of the composites was simulated and analyzed. SiC/A1N composites with 0-30 wt% of A1N were produced by the pressureless sintering method. Phase analysis, densification, and microstructure of the obtained composites were inspected. SiC/A1N ceramics had a porous structure with porosity ranging from 23.77% to 31.74%. Complete 2Hss SiC/A1N solid solution was formed and its content increased with the increment of A1N wt%. Addition of A1N to SiC ceramics gave a harmonic structure with elongated grains morphology. Electrical resistivity and thermoelectric properties of the investigated ceramics were evaluated in the temperature range of 25-1000 K. The results were essentially dependent on A1N content, microstructure and temperature. SiC/A1N composites gave identical behavior of the p-type semiconductors with outstanding thermoelectric properties at high temperatures. The lowest electrical resistivity of 1.5 x 10(5) mu Ohm x cm and the highest Seebeck coefficient of 370 mu V/K were recorded for 30% AIN composite at 1000 K. Figure of merit (ZT) increased dramatically with increasing the A1N content. 30% A1N composites recorded ZT value 130 times larger than that of the 0% A1N composite. Thermoelectric power factor was markedly enhanced by increasing A1N wt%. Thermal stress analysis of the different ceramics was simulated by finite element method up to a temperature of 1773 K. SiC/A1N composites gave splendid thermal stress durability with uniform transition and distribution of heat. SiC/A1N composites are strongly nominated to be used effectively in thermoelectric power generation and high -temperature applications.