NMR spectra on Fe-57 nuclei in YIG containing Y3+ (a) impurities were measured in the temperature range 4.2-360K in zero external magnetic field. The temperature dependencies of satellite lines caused by Y3+(a) impurity were determined. Theoretical description of the temperature behavior of the main and satellite lines has been carried out in the frame of model based on the Bethe-Peierls-Weiss approximation.