Anisotropy of electrical and optical properties in&bgr;-Ga2O3single crystals has been investigated at room temperature. The conductivity and mobility of the degenerate sample along the direction ofbandcaxes are38 &OHgr;−1 cm−1,46 cm2 V−1 s−1,and2.2 &OHgr;−1 cm−1,2.6 cm2 V−1 s−1,respectively. The absorption edges of the insulating sample for light polarizedE//bandE//cwere 4.79 and 4.52 eV, respectively. The rate of the band gap widening with increasing carrier concentration was much larger forE//bthanE//c. The origin of these properties are discussed by considering the crystal and electronic structure of&bgr;-Ga2O3.©1997 American Institute of Physics.