The transcription of small stable non-translated RNA genes (class III genes), directed by RNA polymerase III, is strictly regulated in accordance to physiological state of the cell (growth rate, cell cycle stage, apoptosis, etc.) Post-translational modifications of the polymerase may play the important role in class III gene transcription regulation. Using computational programs searching for potential post-translational modifications sites in proteins (MotifScan, NetPhos 2.0, and Yin-Yan 1.2), possible sites of phosphorylation were identified in all 17 subunits of human RNA polymerase III, and possible sites of reciprocal phosphorylation and glycosilation ("yin-yan" sites) - in 13 subunits. Among the identified sites - 17 sites of phosphorylation in seven subunits are conservative in human, Saccharomyces cerevisiae and Schizosaccharomyces pombe, including two "yin-yan" sites in two subunits. The data obtained can be used for experimental identification of RNA polymerase III modification sites in vivo in cells being in different physiological states.