Аннотация:The magneto-optical transverse Kerr effect (TKE) spectroscopy allows non-contact investigation of nanostructures, giving valuable information about the microstructure of samples. In this paper, within the framework of effective medium approach we analyze the effect of granule size on the magneto-optical spectra of magneticnanocomposites. We consider the influence of various microscopic parameters such as plasma frequency, relaxation time, the coefficient of the anomalous Hall effect inside the granule and on its surface on the amplitude and profile of the TKE spectrum. Three main mechanisms are considered: the quasi-classical size effect, spin–orbit interaction enhancement at the granule surface and change of the percolation threshold.