Questions of change of a physical condition of soil dam of Irkutsk hydroelectric power station are considered eventually. Supervision were spent in a current of ten years. At researches the complex of methods has been applied to definition of geophysical parameters of bulk dams with which help the analysis of speeds of seismic waves as longitudinal and cross-section, electric resistance and natural potential in a body of soil dams was made. By results of works the weakened zones on which in the further works it is given more attention have been allocated. As a whole, the condition of soil dams of Irkutsk hydroelectric power station can be characterized as stable.