We study the effects of spin-orbit (SO) coupling on the reflectance anisotropy spectroscopy of semiconductor surfaces. The 3 * sp s nearest-neighbor tight-binding model with allowance for SO interaction is used to obtain theoretical reflectance anisotropy spectra of clean (110)1 1 ¥ surfaces of III -V semiconductors. We compare our SO-spectra with the experimental spectra and find good agreement between them.