Аннотация:According to our research, the temperature of optical component (O9.7 Iab supergiant) was decreasing and its size was increasing over 7 years (1997-2003). We continue our study of spectral and photometric variability of Cyg X-1 on the basis of the 44-year long series of multicolor photometric observations and many-year-long series of spectral observations that we have accumulated up to now. The photometry performed at the Crimean Station of Sternberg Astronomical Institute (Lomonosov Moscow State University) shows that the variability of the supergiant in this system on the time scale of decades has continued up to now - the mean level of star brightness continues to decrease since 1999 with the variations on smaller time scales superimposed. A remarkable very blue fl are 2009 in U-band coinciding with X-ray are is revealed. Our spectral observations show variations of He I λ 4713 Å absorption line depths. There is a connection between X-ray and optical changes. It is concluded that the fundamental parameters of the supergiant in the system of Cyg X-1 continue to vary. But the conduction of research of these variations is complicated by the possible presence of a variable very hot optically thin gas the evidences of which were revealed.