Аннотация:As a result of our study of spectral and photometric long-term variations of V1357Cyg = Cyg X-1 on the base of the 44-year-long series of multicolor photometric and many-year-long spectro- scopic observations, it is concluded that the fundamental parameters of the supergiant in the system of Cyg X-1 continue to vary on the time scale of decades. There is a connection between X-ray and optical changes. The chaotic variations of X-ray flux, sometimes reaching to "hard" - "soft" state irregular changes, switch on when the U brightness decreases and HeI λ4713Å ab-sorption line depth increases. And inversely - they switch off during U brightness increasing and HeI λ4713Å absorption line depth decreasing. This is may be connected with star size varia-tions, causing outflow gas instability.