Changes of permeability have been measured for as-received amorphous (Fe1-xNix)76Si8B16 alloys after aging for different times at relative low temperatures (65-150℃). The results indicate that the permeability is almost unchanged after aging below 65℃ but it varies obviously above 100℃. The changes of permeability are dependent on the alloy compositions and can be interpreted in terms of the changes of stress, magnetostriction and induced magnetic anisotropy during aging.