Аннотация:We report the results of Cyg X-1 spectral monitoring for 2002 2004. A comparison of observed and non-local thermal equilibrium model profiles for H I, He I and Mg II is given, taking into account the tidal distortion of the Cyg X-1 optical component and its illumination by X-ray emission from the secondary component. We set limits on the main characteristics of the optical component, Teff=30400\plusmn500K and log g=3.31\plusmn0.07, and on the overabundances of He and Mg, [He]/[H]=0.43\plusmn0.06 dex and [Mg]/[H]=0.75\plusmn0.15 dex. The Doppler images were reconstructed by an improved Doppler tomography method on the basis of nine He II (?=4686Å) profiles from 2003 (the \lsquosoft\rsquo X-ray state) and six profiles from 2004 (the \lsquohard\rsquo X-ray state). This allowed us to set limits on the black-hole-to-supergiant mass ratio (1/4)=slant MX/MO=slant (1/3).