In the paper, the action of metal ions on the human serum albumin had been investigated by fluorescence quenching method. The results showed that Cu²⁺, Mn²⁺, Co²⁺, Cr³⁺,Eu³⁺,Ni²⁺ may bind to human serum albumin and that the fluorescence of human serum albumin may be quenched by nonradiative energy transfer. In terms of Förster type dipoledipole nonradiative energy transfer the distance between the Trp-214 and the bound Cu²⁺ in the first copper-binding site was calculated and found to be about 1.20nm.