  The dependence of initial magnetic permeability {\mu}i of based on the
Fe-Si-B amorphous and nanocrystalline alloys on the {\gamma}-irradiation dose
was investigated by the method of inductance factor determination. It was
determined that the alloying of amorphous Fe-Si-B alloys by nickel and
molybdenum increases the radiation sensitivity of the {\mu}i. Initial magnetic
permeability of nanocrystalline magnetic alloys is less sensitive to the action
of {\gamma}-irradiation as compared with the alloyed amorphous alloys. Has been
suggested that radiation influence on the initial magnetic permeability are
caused by creation of non-magnetic incorporation in structure of amorphous
alloys as well as amorphous matrix of nanocrystalline alloys.
