At the present time there is a tendency for developing and instrumentation of large power generating turbo-sets with torsional vibration control systems. Achievements of both foreign and Russian scientists and researchers in matters of torsional vibration monitoring and control system of power generating unit shaft train, operating processing techniques and outcome analysis are given in this article. The reasons that are cause of natural and forced vibrations were thoroughly examined. The analysis of research work accomplished by Moscow State Technical University (MSTU), Ural Federal University (UrFU) and other organizations was done. Key points of the torsional vibration analysis algorithm are studied as well as the critical analysis of some results is given. One should notice that the new diagnostic quality of a shaft train state and unit protect quality improvement thoroughly examined in MSTU research works are beforehand and groundless. It is another matter that the permanent torsional vibration monitoring of power generating turbo-sets in service allows us avoiding continuous operation at large torsional vibration conditions and also evaluating the unit life time due to rotor fatigue cumulations.