For the purpose of a further study of the sintering process of beta-BN grains into polycrystalline compacts, a study was made of the influence of sintering temperature and grain size on the microstructure, width of the x-ray diffraction lines, and certain physical properties of polycrystalline specimens of beta-BN. Sintering of beta-BN grains occurs in the 1400-3400 K range. With an increase in temperature, contact interaction of the grains is strengthened, coarsening takes place, and a decrease in concentration and size of the pores occurs. The polycrystalline specimens obtained at sintering temperatures of 2800-3400 K have high electrical conductivity, microhardness, thermal conductivity, density and strength.