Attenuation of spin waves in a structure with a strongly anisotropic bismuth-containing high-temperature superconductor (HTSC) is studied experimentally in the temperature range from 60 to 120 K. A correlation in the behavior of the temperature dependence of the attenuation and resistance is discovered. The explanation of the obtained results is based on the evaluation of the hf surface impedance of the structure within the frames of the model of thermally activated motion of vortices of the magnetic flux.</p