Heparin, chodroitin sulfates A, B, C, clofibrate and its derivatives as well as diphenyl disulfonate substituted the fluorescent probe I-aniline naphthalene-8-sulfonate in blood plasma low density lipoproteins. Constants of association for complexes of low density lipoproteins-heparin and chondroitin sulfate C, calculated on the basis of these data, were equal to 1.15.10(6) and 0,46.10(6) M-1, respectively. At the some time, the ligands studied altered the lipoprotein charges.