Al- and B-doped 3C-SiC ceramics were prepared by hot-pressing powder compacts containing submicrometer-sized -SiC, precursors of 5wt% nanosized -SiC, and an optional additive (Al or B) in an Ar atmosphere. Electron probe microanalysis (EPMA) investigation on the obtained specimens revealed that a portion of the doped Al and B atoms substituted the zinc blende lattice sites. The temperature-dependent electrical resistivity data of the Al- and B-doped SiC specimens were measured in the 4-300K range and compared with those of an undoped specimen. The Al- and B-doped SiC specimens exhibited resistivities that were as high as similar to 10(3)cm at room temperature and similar to 10(5) and similar to 10(4)cm, respectively, below 100K. These values are larger than those of the undoped SiC specimen by a factor of similar to 10(4). Such high resistivities of the impurity-doped specimens are attributable to the carrier compensation by the Al- and B-derived acceptors located well above the valence-band edge of 3C-SiC. Photoluminescence investigation revealed that the Al- and B-doped specimens exhibited emission profile below 2eV, implying the existence of the acceptors.