Аннотация:We report the results of V1357Cyg optical spectral observations over 2003-2004. The comparison of observed and non-LTE model profiles for HI, HeI and MgII is given taking into account tidal distortion of Cyg X-1 optical component and its illumination by X-ray radiation of secondary one. We set restrictions on the optical component main characteristics T[eff] = 30400\plusmn500K, log g = 3.31\plusmn0.07 and overabundance of He and Mg: [He/H] = 0.43 dex, [Mg/H] = 0.59 dex. Also we found overabundances of Si, N, C and O with Al solar abundance.