Аннотация:Broad-band photometric observations of the black hole candidate Cyg X-1 were carried out during 1995-1998 in the frame of the compaign of coordinated observations, at different observatories of the former Soviet Union. All data have been reduced to a homogenious set/ Comparison of the optical and X-ray data clearly shows the existence of several kinds of variability. The cross-correlation analysis of the whole data set permitted us to find correlations between optical and X-ray data on different time scale.